@misc{SalmonRateRengeletal., author = {Salmon, S. Ursula and Rate, Andrew W. and Rengel, Zed and Appleyard, Steven and Prommer, Henning and Hinz, Christoph}, title = {Reactive transport controls on sandy acid sulfate soils and impacts on shallow groundwater quality}, series = {Water Resources Research}, volume = {50}, journal = {Water Resources Research}, number = {6}, issn = {1944-7973}, doi = {10.1002/2013WR014404}, pages = {4924 -- 4952}, abstract = {Disturbance or drainage of potential acid sulfate soils (PASS) can result in the release of acidity and degradation of infrastructure, water resources, and the environment. Soil processes affecting shallow groundwater quality have been investigated using a numerical code that integrates (bio)geochemical processes with water, solute, and gas transport. The patterns of severe and persistent acidification (pH < 4) in the sandy, carbonate-depleted podzols of a coastal plain could be reproduced without calibration, based on oxidation of microcrystalline pyrite after groundwater level decrease and/or residual groundwater acidity, due to slow vertical solute transport rates. The rate of acidification was limited by gas phase diffusion of oxygen and hence was sensitive to soil water retention properties and in some cases also to oxygen con-sumption by organic matter mineralization. Despite diffusion limitation, the rate of oxidation in sandy soils was rapid once pyrite-bearing horizons were exposed, even to a depth of 7.5 m. Groundwater level movement was thus identified as an important control on acidification, as well as the initial pyrite content. Increase in the rate of Fe(II) oxidation lead to slightly lower pH and greater accumulation of Fe(III) phases, but had little effect on the overall amount of pyrite oxidized. Aluminosilicate (kaolinite) dissolution had a small pH-buffering effect but lead to the release of Al and associated acidity. Simulated dewatering scenarios highlighted the potential of the model for risk assessment of (bio)geochemical impacts on soil and groundwater over a range of temporal and spatial scales.}, language = {en} } @inproceedings{BrueckSchulteOverbergPohleetal., author = {Br{\"u}ck, Yasemine and Schulte-Overberg, Philipp and Pohle, Ina and Hinz, Christoph}, title = {{\"O}kohydrologische Systeme im Wandel: NDVI von Tagebaufolgelandschaften}, series = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, booktitle = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, editor = {Sch{\"u}tze, Niels and M{\"u}ller, Uwe and Schwarze, Robert and W{\"o}hling, Thomas and Grundmann, Jens}, publisher = {Technische Universit{\"a}t}, address = {Dresden}, pages = {S. 113}, abstract = {Tagebau(folge)landschaften bieten gute M{\"o}glichkeiten den Wandel {\"o}kohydrologische Systeme aufgrund ver{\"a}nderter Umweltbedingungen zu untersuchen: Im Zuge des Tagebaubetriebs wird die Vegetation vollst{\"a}ndig entfernt, nach dem Tagebau w{\"a}chst die Vegetation entweder durch aktive Rekultivierung oder nat{\"u}rliche Sukzession wieder auf. Von Interesse ist, ob und wie bzw. wie schnell sich die Tagebaufl{\"a}chen von der St{\"o}rung erholen und {\"a}hnliche Bedingungen wie vor dem Tagebau bzw. auf ungest{\"o}rten Fl{\"a}chen herrschen. Klimatische, geomorphologische und {\"o}kologische Gegebenheiten sowie die Rekultivierungsstrategie spielen eine große Rolle in der Phase der Rehabilitation und bestimmen die Rate der Wiederbesiedlung mit Pflanzen bzw. deren Wachstum. Der NDVI (normalisierter differenzierter Vegetationsindex) bietet die M{\"o}glichkeit generelle Muster der Vegetation quantitativ zu detektieren, um die Regenerationsrate der Vegetation f{\"u}r verschiedene Klima- und {\"O}koregionen abzusch{\"a}tzen. Wir analysierten den MODIS Terra NDVI (achtt{\"a}gliche Werte) f{\"u}r Tagebaulandschaften verschiedener Klimate ({\"a}quatoriale, trockene, warm gem{\"a}ßigte und Schnee-Klimate nach K{\"o}ppen-Geiger) im Zeitraum 2001 bis 2015. Es wurden Kohletagebaue betrachtet, da diese gut definierte Chronosequenzen der St{\"o}rung erzeugen. Bei der Analyse der NDVI-Zeitreihen sollten Charakteristiken der Rehabilitationsphase erfasst werden. Um die r{\"a}umliche Heterogenit{\"a}t der Zellen (ca. 250 x 250 m²) der Tagebaulandschaft abzubilden, wurde je Tagebau eine hierarchische Clusteranalyse durchgef{\"u}hrt. Die einzelnen Zeitreihen der Cluster wurden mit einer Methode zur Detektion von Bruchpunkten und zur Zeitreihenzerlegung auf Konsistenz bez{\"u}glich Eigenschaften der Zeitreihen (Beginn des Tagebaus, Ende des Tagebaus/Beginn der Rehabilitation, Rate der Rehabilitation) untersucht. Die Clusteranalyse f{\"u}hrt zu einer Einordnung der Zellen in vom Tagebau nicht direkt beeinflusste Fl{\"a}chen, aktiven Tagebau und in der Rehabilitation befindliche Fl{\"a}che verschiedenen Alters bzw. rehabilitierte Fl{\"a}chen. Das Zeitfenster der Entfernung der Vegetation kann im NDVI-Signal identifiziert werden, es zeigt sich meist in einer abrupten {\"A}nderung des NDVI. Die Rehabilitationsphase hingegen verl{\"a}uft graduell und kann mehrere Jahre bis Jahrzehnte andauern. Die Zeitreihenzerlegung zeigt auf, dass in der Rehabilitationsphase der Trend dominiert, w{\"a}hrend mit Voranschreiten der Rehabilitation die Saisonalit{\"a}t im NDVI-Signal vorherrschend wird. Durch die ermittelte Rate der Rehabilitation k{\"o}nnen die Fl{\"a}chen innerhalb eines Tagebaus miteinander verglichen werden. Die mittlere Rehabilitationsrate der Tagebaue kann in Zusammenhang mit den vorherrschenden hydroklimatischen Bedingungen der Klimazonen und mit Rekultivierungsstrategien gebracht werden. Zudem ist auch eine Betrachtung hydrometeorologischer Gr{\"o}ßen zur Erkennung von kurzzeitigen Ver{\"a}nderungen des Pflanzenwachstums im NDVI-Signal m{\"o}glich.}, language = {de} } @inproceedings{CaviedesVoulliemeAndezhathMohananBruecketal., author = {Caviedes-Voullieme, Daniel and Andezhath Mohanan, Anju and Br{\"u}ck, Yasemine and Zaplata, Markus Klemens and Hinz, Christoph}, title = {Effect of surface water redistribution on vegetation encroachment in the constructed H{\"u}hnerwasser catchment}, series = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, booktitle = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, editor = {Sch{\"u}tze, Niels and M{\"u}ller, Uwe and Schwarze, Robert and W{\"o}hling, Thomas and Grundmann, Jens}, publisher = {Technische Universit{\"a}t}, address = {Dresden}, pages = {S. 91}, abstract = {The artificial H{\"u}hnerwasser catchment has experienced a significant and monitored evolution since 2005, changing from a post-mining landscape to an almost fully vegetated ecosystem. The early stages showed a fast rate of ecohydrological evolution with changing dominating processes and feedbacks. The evolution of rill vegetation encroachment is one of such complex co-evolving processes. We hypothesise that rill vegetation encroachment is driven by the evolution of the hydrologic/hydraulic regime of the rill network, which in turn affects the regime, potentially creating a stabilising positive feedback. We further hypothesise that rill vegetation occurs later than hillslope vegetation, and follows a particular establishment and encroachment timeline in response to the changing hydrological/hydraulic regimes. That is, the early runoff-dominated regime results in higher flows, velocities, transport and erosion capacity, thus favouring seed flushing and seedling uprooting. On the other hand, as the system transitions from a runoffdominated into an infiltration- and ET-dominated system, flow, velocity, transport and erosion capacity in the rill network are reduced, making seed establishment in the rills more likely. We explore these hypothesis with two complementary approaches: an analysis of the spatiotemporal distribution of vegetation and a process-based numerical modelling study. Firstly, we assess aerial photography of rill vegetation encroachment between 2007 and 2012 in terms of several vegetation types to derive temporal indicators of encroachment. The analysis reveals that in the initial stages, a rill network developed in the hillslope. Shortly after vegetation first established on hillslopes, the rill network became progressively vegetated. Different pioneering species established heterogeneously, at different times and encroached into the rills at different rates. However, despite the volume of data, it is difficult to assess which are the governing and limiting processes which respectively drive and constrain how and at which rate vegetation encroaches into the rills. In consequence, a pilot modelling study to identify the relative relevance of rill network geometry, bare soil infiltration, hillslope vegetation heterogeneity and intra-storm variability on the hydraulic response of the rill network and its possible impact on encroachment. The overall results suggest that vegetation encroachment may be controlled by the rill network hydraulic regime, but such regime is the result of a complex superposition of responses of all the aforementioned factors, of which rill geometry appears to be a dominant one. Furthermore, the simulations showed that vegetation spatial heterogeneity has an impact on the hydraulic regime coupled to the presence of temporal rainfall variability. Altogether, these results show that the governing coevolving ecohydrological processes are interacting and are strongly affected by spatial and temporal heterogeneities.}, language = {en} } @inproceedings{PohleGaedekeKochetal., author = {Pohle, Ina and G{\"a}deke, Anne and Koch, Hagen and Sch{\"u}mberg, Sabine and Hinz, Christoph}, title = {Kann Wasserressourcenbewirtschaftung die Unsicherheiten projizierter Klimafolgen auf den Abfluss vermindern? - Ein Vergleich in zwei hydrologisch {\"a}hnlichen Einzugsgebieten mit unterschiedlichem Ausmaß des Bewirtschaftungseinflusses}, series = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, booktitle = {M³ - Messen, Modellieren, Managen in Hydrologie und Wasserressourcenbewirtschaftung. Beitr{\"a}ge zum Tag der Hydrologie am 22./23. M{\"a}rz 2018 an der Technischen Universit{\"a}t Dresden}, editor = {Sch{\"u}tze, Niels and M{\"u}ller, Uwe and Schwarze, Robert and W{\"o}hling, Thomas and Grundmann, Jens}, publisher = {Technische Universit{\"a}t}, address = {Dresden}, pages = {S. 30}, abstract = {Studien zum Einfluss des zuk{\"u}nftigen Klimawandels auf das Abflussgeschehen fokussieren oft auf die Fortpflanzung von Unsicherheiten in Modellkaskaden, ber{\"u}cksichtigen meist jedoch die Wasserressourcenbewirtschaftung nur ungen{\"u}gend. Wir untersuchten den Einfluss der Wasserressourcenbewirtschaftung auf die Abflussvariabilit{\"a}t und die Fortpflanzung von Unsicherheiten von Klimaprojektionen auf Abflusssimulationen in den Einzugsgebieten von Spree (bis Pegel Große Tr{\"a}nke: 6200 km²) und Schwarzer Elster (5700 km²). Die Einzugsgebiete {\"a}hneln sich hinsichtlich Klima, Topographie, Boden und Landnutzung, jedoch ist das Spreeeinzugsgebiet st{\"a}rker durch den Braunkohletagebau und die damit verbundenen Bewirtschaftung gepr{\"a}gt und durch einen h{\"o}heren Speicherausbaugrad gekennzeichnet. Um zwischen Bewirtschaftungseinfl{\"u}ssen und meteorologischen Einfl{\"u}ssen zu separieren, wurden f{\"u}r den Zeitraum 1961-2005 beobachtete Abfl{\"u}sse mit durch das Modell SWIM rekonstruierten nat{\"u}rlichen (d.h. ohne Bewirtschaftungseinfluss) Abfl{\"u}ssen der Vergangenheit verglichen. M{\"o}gliche Einfl{\"u}sse des Klimawandels wurden f{\"u}r den Zeitraum 2018-2052 auf Grundlage von 3 Szenarien des statistischen Regionalmodells STAR (je 100 Realisierungen) mit SWIM (nat{\"u}rliche Abfl{\"u}sse) und dem Langfristbewirtschaftungsmodell WBalMo (bewirtschaftete Abfl{\"u}sse) modelliert. Die Analyse erfolgte mit Fokus auf Saisonalit{\"a}t, Oszillation, Verteilung und r{\"a}umliche Variabilit{\"a}t der Abfl{\"u}sse. Der Vergleich zwischen beobachteten und nat{\"u}rlichen Abfl{\"u}ssen der vergangenen Jahrzehnte zeigt, dass die zwischenj{\"a}hrliche Abflussvariabilit{\"a}t im Spreeeinzugsgebiet st{\"a}rker durch Grubenwassereinleitungen als durch nat{\"u}rliche hydrologische Prozesse bestimmt wurde. Zus{\"a}tzlich f{\"u}hrt der h{\"o}here Speicherausbaugrad dazu, dass die kurzzeitliche und saisonale Variabilit{\"a}t im Spreeeinzugsgebiet geringer als im Einzugsgebiet der Schwarzen Elster ist. Simulationen mit Klimaszenarien, welche steigende Jahresmitteltemperaturen und einen R{\"u}ckgang der Niederschlagsjahressummen enthalten, f{\"u}hren zu deutlichen Abflussr{\"u}ckg{\"a}ngen. Die Unterschiede der nat{\"u}rlichen Abfl{\"u}sse beider Einzugsgebiete sind gering, die Unsicherheiten der Klimaprojektionen werden durch die hydrologische Modellierung verst{\"a}rkt. Die nat{\"u}rlichen und bewirtschafteten Abfl{\"u}sse der Schwarzen Elster unter Klimawandel unterscheiden sich kaum. Im Spreeeinzugsgebiet zeigt sich eine deutliche Verringerung der Variabilit{\"a}t und Unsicherheiten unter Klimawandel von den nat{\"u}rlichen zu den bewirtschafteten Abfl{\"u}ssen. Die Analysen zeigen, dass effektive Wasserressourcenbewirtschaftung die Abflussvariabilit{\"a}t verringern kann und damit auch dazu beitragen kann, die sich aus Klimawandelprojektionen ergebenden Unsicherheiten zu vermindern. Einzugsgebiete mit einem hohen Ausbaugrad weisen weniger Vulnerabilit{\"a}t bez{\"u}glich klimatischer {\"A}nderungen auf. Dies unterstreicht die Bedeutung von Wasserresourcenbewirt-schaftungf{\"u}r die Anpassung an den Klimawandel.}, language = {de} } @inproceedings{CaviedesVoulliemeHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {The role of topography and intra-annual rainfall variability in semi-arid vegetation self-organisation: a multi-scale modelling study}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Coevolution of hydrological and vegetation dynamics in semi-arid regions has been widely observed to result in vegetation self-organisation (VSO). Many hypothesis of VSO's underlying ecohydrological processes and feedbacks have been studied relying on mathematical models, which have been key to evaluate the sensitivity of ecohydrological systems to environmental factors and drivers. Although this ecohydrological coevolution is essentially multiscale, researchers have continued to be constrained by the simplicity of the models which are unable to cope with the multiscale, process-based complexity of fast-moving surface water over complex topographies driven by varying rainfall, during decade-to-century long VSO processes. This limitation has not allowed deep exploration of the role and sensitivity of key environmental factors such as topography and rainfall variability, and the lack of proper hydrodynamics still constrains adequate sediment transport modelling and its feedback effects on VSO. We hypothesize that the intra-storm water redistribution by surface runoff at the hillslope scale is strongly controlled by both topography and storm intensity and may control VSO. This requires for these environmental factors to be accurately represented in models and their their hydraulic and hydrological effects properly reflected. This work provides the first systematic study of the effects of topography and intra-annual rainfall distributions on vegetation band formation at the hillslope scale. Simulations were performed with a physically-based numerical model solving the Zero-Inertia approximation to the shallow water equations for surface flow coupled to the HilleRisLambers-Rietkerk vegetation model, allowing to explicitly represent arbitrary topography. An idealized study of ecohydrological evolution over 30 years was performed, solving with a temporal resolution in the seconds scale. Plane, convex and convex hillslope topologies with different slopes were used, while forcing the model with different annual rainfalls along a semi-arid rainfall gradient, with discrete events of different frequencies. We describe results in terms of evolution of total biomass, hydrological water balance, and of the spatial properties of banded vegetation. Results show that both topography and intra-annual rainfall distribution can play a shaping and governing role in VSO by controlling surface water redistribution and the hydrologic water balance. Increasing slopes favours runoff over infiltration, reducing the available water for vegetation and resulting in different evolutions of vegetation band geometry and band migration. Hillslope topology plays a strong role in the internal water redistribution of the system. Plane and convex surfaces behave similarly, but concave surfaces exhibit a different ecohydrological behaviour, despite the very small topological differences. Different intra-annual rainfall distributions result in different rainfall intensities for the same total annual rainfall which strongly affect the band formation and evolution process: higher intensities lead to less available water, to which vegetation adapts by spatially clustering in bands with different geometrical properties. The study also shows that it is computationally feasible (a few hours runtime) to perform decade-to-century long simulations of these systems with physically-based numerical models paving the way to simulate natural systems with arbitrary topography and high-resolution rainfall data, and is a first step in introducing physically-based sediment transport processes and feedbacks in these studies.}, language = {en} } @inproceedings{BrueckAndezhathMohananCaviedesVoulliemeetal., author = {Br{\"u}ck, Yasemine and Andezhath Mohanan, Anju and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Zaplata, Markus Klemens}, title = {Spatio-temporal development of rill vegetation in the H{\"u}hnerwasser Catchment}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The artificial catchment "H{\"u}hnerwasser" was built in a post-mining landscape, as a field experiment to observe and monitor early-development ecosystems at hillslope scale. Early on, rain-induced rill and channels formation was observed, followed by vegetation growth in between rills, and later on inside the rills. In this work, we aim to describe the temporal evolution of the spatial distribution of rill vegetation. In general terms, we hypothesize four different encroachment patterns might occur: (1) The vegetation spreads from the top of the rills downstream. The underlying hypothesis would be a higher establishment probability due to a lower velocity of surface runoff and therefore less transport probability compared to downstream rill segments. (2) The vegetation starts growing downstream and moves upwards. In this case we can hypothesize that the spatial distribution of the vegetation is dominated by water availability, which is higher or more stable downstream. (3) The vegetation encroaches from the sides into the rills, meaning that inter-rill vegetation governs vegetation encroachment inside the rills. (4) If no patterns are detected it might mean that the encroachment process depends strongly on very local conditions, or perhaps that the underlying assumption of an initially homogeneous seed distribution is false. To investigate the rills formation and rill vegetation encroachment processes, rills and vegetation patches inside these rills were identified and digitized from aerial photographs of the catchment from 2007 to 2012. Different vegetation types were identified based on the colour and texture of the patches. The geometrical properties of the rill segments and vegetation patches were used to define how the different vegetation types have distributed in space and how this distribution has changed over time. Rill mapping reveals a large increase of rill area from 2007 to 2008 and only a small rise from 2008 to 2009. Starting in 2010 dense vegetation prevents a precise mapping of the rills in the aerial photographs, so we assume that there is no change in rill area from 2009 to 2012. In 2007 vegetation covered only 1.4\% of the rill area. There is only a small increase of this area in 2008 compared to the later years. In 2012 more than 50\% of the rill area is covered by plants. Ten different vegetation types have been identified in the aerial photographs, starting with two types in 2007. By 2012 nine types are spotted in the rills of the catchment. Some of these vegetation types show an encroachment from up- to downstream (e.g. Tussilago farfara), some from down- to upstream like Phragmites australis, whose creeping rhizomes can also promote such spreading. Others reveal no patterns. To better assess and identify the underlying processes leading to these encroachment processes shown by the different vegetation types further data analysis -e.g. comparison with ground based vegetation mapping- and process-based hydrological modelling is necessary to fully explain these observations and assessing additional competition effects, which may be at play.}, language = {en} } @inproceedings{CaviedesVoulliemeAndezhathMohananBruecketal., author = {Caviedes-Voulli{\`e}me, Daniel and Andezhath Mohanan, Anju and Br{\"u}ck, Yasemine and Hinz, Christoph}, title = {Rill hydrodynamics and its impact on rill vegetation encroachment: a modelling study of the constructed H{\"u}hnerwasser catchment}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The H{\"u}hnerwasser catchment is a monitored, early-development constructed catchment within the Lower Lausatia post-mining landscape in Germany. Observations have shown that a sequence of landscape-forming processes occurred, including the initial vegetation establishment stages, which are the main interest of this study. In the initial stages of geomorphic development a surface drainage network of rills was formed as vegetation started to appear on the hillslopes and subsequently inside the rill network. Observations and analysis of the rill vegetation establishment suggest that different vegetation types encroach into the rill network at different times, rates and form different directions. We hypothesize that these encroachment processes may respond to the runoff properties of the catchment at such time: velocity distribution in the rills might play a significant role in flushing seeds in high-velocity reaches of the rill network, thus favouring the appearance of vegetation in low-velocity regions. Consequently, the goal of this study is to assess the magnitudes and spatiotemporal behaviour of velocity in the rill network, to assess its possible impact on seed flushing and rill vegetation encroachment. One rill subcatchment of H{\"u}hnerwasser was selected to perform an explorative study of rill hydrodynamics and their impact on vegetation establishment. Two vegetation states were simulated: bare hillslopes and vegetated hillslopes. The vegetated cover polygons were obtained from digitized aerial photography, and stochastically dissagregated 10-minute resolution precipitation data were used, selecting events with early, middle and late peak storm intensities. A 2D explicit finite volume scheme solving the Zero-Inertia approximation to the shallow water equations was used to simulate surface flow in the subcatchment. The preliminary modelling results suggest that that there is no clear overall velocity gradient in the downstream direction along the rills. In fact, velocity in the rills may increase or decrease along the rill following local topography and rill geometry. Consequently, no global trend for the probability of seeds being transported can be established. The results also shows that varying rainfall intensity and rainfall intrastorm distribution -in the absence of hillslope vegetation- does not affect the rill locations of maximum velocities, but mostly affect the magnitude of velocity. In the presence of hillslope vegetation -and thus heterogeneous infiltration conditions in the hillslopes- the spatial distribution of velocity is strongly affected, and can be in fact governed not by topography or rill geometry, but by the spatial heterogeneity of infiltration capacity. Furthermore, the time at which maximum discharge and velocities occur may not match that of maximum intensity. That is, emerging temporal dynamics arise due to the introduction of spatial heterogeneity, which also manifests in the fact that outflow from the subcatchment exhibits a intensity-thresholded behaviour.}, language = {en} } @inproceedings{CaviedesVoulliemeHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Convergent biomass, divergent patterns: Can initial conditions govern vegetation self-organisation?}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Vegetation self-organisation in water-limited ecosystems in semi-arid climates has been extensively studied by means of numerical simulation using a set of different reaction-diffusion-equations. Most of such models and studies have been concerned with the long-term steady ecohydrological states on domains with periodic boundaries and forced by steady rainfall, whilst little interest has been given to the transient states which lead to them as well as the spatiotemporal multiscale nature of the feedback processes. It is generally accepted that alternative random initial biomass distributions do not significantly affect the resulting steady state vegetation patterns. However, the role of the initial hydrological conditions -initial surface and subsurface water- has not been explored, mainly due to the interest in the long-term steady state. Nonetheless, vegetation patterns are directly linked to the water distribution occurring at much shorter time scales than vegetation growth, and because they have been shown to be sensitive to annual rainfall, it is reasonable that the initially available water will also play a role. We therefore hypothesize that the initially available water will play a role in the transient process leading to a steady ecohydrological state, and that the steady vegetation patterns will differ in response to the water availability in time during the entire process. In this contribution we explore the role of initial hydrological conditions on both the transient and longterm steady ecohydrological state. A simulation study was performed using the HilleRisLambers-Rietkerk ecohydrological model on a flatland varying the initial available water whilst also spanning the rainfall gradient (90 - 360 mm/year) . The results were assessed in terms of the evolution and steady state of total biomass yield and hydrological water balance, as well as a quantitative assessment of both transient and steady vegetation patterns. The results show that the initially available water does play a role, not only in the early transient state, but in the long-term steady state, and indeed in the geometry of the converged vegetation pattern. Furthermore, although the steady state biomass yield may be the same for varying initial conditions, the final patterns still differ, e.g., a reduction to one-fourth initial water availability results in more but smaller vegetation patches, while a reduction to one-eigth initial water results in less, but larger patches, and a reduction to one-sixteenth results in a completely new pattern, although total biomass is the same for all. This suggests that long-term average rainfall may govern the total biomass but the initial conditions may play a relevant shaping role in the long term spatial distributions of steady ecohydrological states of water-limited ecohydrosystems. This is relevant, among other reasons, because the resilience of the system is associated to the vegetation patterns. It also suggests that neither the temporal distribution of rainfall nor the system's evolution cannot be neglected to understand the environmental factors which lead to a steady ecohydrological state, since multiple paths may be possible. This warrants further developments from the ecohydrological modelling community and further study of transient states through process-based models.}, language = {en} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Dynamik der initialen ({\"o}ko-) hydrologischen Entwicklung - Modellierung von Anfangsbedingungen und Wasserfl{\"u}ssen in einem exemplarischen Einzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 20}, language = {de} } @inproceedings{MaurerPohleOeseretal., author = {Maurer, Thomas and Pohle, Ina and Oeser, Anne and Sieber, Andr{\´e} and Hinz, Christoph}, title = {Investigating the interrelations between throughfall, meteorological variables and vegetation structure in a developing hydrological catchment}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {In landscapes with heterogeneous vegetation structure, interception and throughfall patterns produce spatiotemporal variability of soil moisture. This variability is important for eco-hydrological processes, in particular on small spatial scales up to the catchment scale. Throughfall depends on vegetation structure, whereas vegetation development is presumably co-determined by the spatio-temporal distribution of throughfall itself. In addition to vegetation structure, meteorological factors like wind speed and rainfall intensity also have an impact on throughfall. The objective of this study is to quantify the influence of vegetation structure and meteorological variables on spatial (and in the long run the temporal) variability of throughfall. For that purpose, we developed an approach combining field methods, image analysis and multivariate statistics. The 6-ha constructed catchment ‚H{\"u}hnerwasser' (aka Chicken Creek, southern Brandenburg, Germany) offers ideal conditions for the investigation of eco-hydrological feedback processes. After more than 10 years of development, vegetation structure on the catchment is spatially heterogeneous and evolves through natural succession. Furthermore, complementary meteorological data are available on-site. Throughfall was measured using 50 tipping-bucket rain gauges, which are aligned along two transects in 0.5 and 1 m heights, covering the dominating vegetation types on the catchment (e.g., robinia, sallow thorn, reed, reedgrass, herbs). The spatial distribution of vegetation structures around each measurement site was recorded with hemispheric photographs, which were subsequently analyzed using image processing techniques. Two weather stations provide reference values for precipitation and relevant meteorological variables for wind speed and direction, air humidity, temperature and irradiation. The amount and distribution of precipitation measured in scarcely vegetated areas of the catchment widely correspond with values from the reference weather stations. Under dense vegetation, very heterogeneous values were recorded, which can be explained by i) canopy interception, and ii) fetching effects. The results of this study can serve as basis for interception models and may also contribute to complex eco-hydrological models.}, language = {en} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Flow processes on the catchment scale - modeling of initial structural states and hydrological behavior in an artificial exemplary catchment}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Landscapes that are heavily disturbed or newly formed by either natural processes or human activity are in a state of disequilibrium. Their initial development is thus characterized by highly dynamic processes under all climatic conditions. The primary distribution and structure of the solid phase (i.e. mineral particles forming the pore space) is one of the decisive factors for the development of hydrological behavior of the eco-hydrological system and therefore (co-) determining for its - more or less - stable final state. The artificially constructed ‚H{\"u}hnerwasser' catchment (a 6 ha area located in the open-cast lignite mine Welzow-S{\"u}d, southern Brandenburg, Germany) is a landscape laboratory where the initial eco-hydrological development is observed since 2005. The specific formation (or construction) processes generated characteristic sediment structures and distributions, resulting in a spatially heterogeneous initial state of the catchment. We developed a structure generator that simulates the characteristic distribution of the solid phase for such constructed landscapes. The program is able to generate quasi-realistic structures and sediment compositions on multiple spatial levels (1 cm up to ∼ 100 m scale). The generated structures can be i) conditioned to actual measurement values (e.g., soil texture and bulk distribution); ii) stochastically generated, and iii) calculated deterministically according to the geology and technical processes at the excavation site. Results are visualized using the GOCAD software package and the free software Paraview. Based on the 3D-spatial sediment distributions, effective hydraulic van-Genuchten parameters are calculated using pedotransfer functions. The hydraulic behavior of different sediment distribution (i.e. versions or variations of the catchment's porous body) is calculated using a numerical model developed by one of us (Caviedes-Voulli{\`e}me). Observation data are available from catchment monitoring are available for i) determining the boundary conditions (e.g., precipitation), and ii) the calibration / validation of the model (catchment discharge, ground water). The analysis of multiple sediment distribution scenarios should allow to approximately determine the influx of starting conditions on initial development of hydrological behavior. We present first flow modeling results for a reference (conditioned) catchment model and variations thereof. We will also give an outlook on further methodical development of our approach.}, language = {en} } @inproceedings{PohleHuSchaafetal., author = {Pohle, Ina and Hu, Yuzhu and Schaaf, Wolfgang and Gerwin, Werner and Maurer, Thomas and Hinz, Christoph}, title = {Hydrogeochemische Signaturen der Einzugsgebietsentwicklung - die Rolle der Calcium- und Sulfatfreisetzung im H{\"u}hnerwassereinzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 5}, language = {de} } @inproceedings{CaviedesVoulliemeDominFernandezPatoetal., author = {Caviedes-Voulli{\`e}me, Daniel and Domin, Andrea and Fern{\´a}ndez-Pato, Javier and Hinz, Christoph}, title = {A numerical study on the influence of m{\`i}crotopography on ra{\`i}nfall-runoff-infiltration partitioning}, series = {4th International Symposium of Shallow Flows (ISSF 2017), Eindhoven University of Technology, The Netherlands, 26.-28.06.2017}, booktitle = {4th International Symposium of Shallow Flows (ISSF 2017), Eindhoven University of Technology, The Netherlands, 26.-28.06.2017}, abstract = {Microtopographic features, although minute relative to the hillslope scales, are not insignificant in terms of runoff generation, rain-runoff-infiltration partitioning and overall hillslope hydrological signals. As-sessing the effects of such small scale features, arguably requires mathematical models that can cope with microtopraphic complexity to adequately represent surface water dynamics, which in turn deter-mine hydrological signals at the hillslope scale. In this work, rain-runoff simulations are perfomed with a 2D shallow water model on a rectangular domain representing a hillslope with an idealized 2D sinusoidal microtopography. Several combinations of slope, wavelength and amplitudes were used to create over 500 surfaces on which simulations were performed in order to assess their hydrological response in terms of rainfallrunoff-infiltration partitioning. The results were analysed through several dimensionless indices which allow to observe the dependency of characteristic hydrological responses to mi-crotopography properties. They reveal a complex dependency of hydrological signatures to surface microtopography. In particular, the results show that the fraction of rainfall that results in infiltration is increased following a particular non-linear dependency on surface smoothness. Additionally, hydrograph properties and surface flow connectivity also show emerging patterns in response to microtopography.}, language = {en} } @inproceedings{PohleGaedekeKochetal., author = {Pohle, Ina and G{\"a}deke, Anne and Koch, Hagen and Sch{\"u}mberg, Sabine and Hinz, Christoph}, title = {Can water resources management alleviate the uncertainty of projected climate change impacts on river discharge? - A comparative study in two hydrologically similar catchments with different level of management}, series = {International Soil and Water Assessment Tool Conference. SWAT 2017, June 28 - 30, Warsaw, Poland, Book of Abstracts}, booktitle = {International Soil and Water Assessment Tool Conference. SWAT 2017, June 28 - 30, Warsaw, Poland, Book of Abstracts}, pages = {10 -- 11}, abstract = {Climate change impact studies are associated with error propagation and amplification of uncertainties through model chains from global climate models down to impact (e.g. hydrological) models. The effect of water management, which reduces discharge variability, is often not considered in climate change impact studies. Here, we investigated how water resources management influences discharge variability and uncertainty propagation of climate change scenarios by combining the analyses of observed flow records and model-based climate change impact simulations. Two neighbouring catchments, the Schwarze Elster River (Germany) and the Spree River (Germany and Czech Republic) which are similar in climate, topography and land use, but different in terms of water resources management were chosen as study area. The intense water resources management in the Spree River catchment includes a high reservoir capacity, water use in terms of mining discharges and water withdrawals by power plants as well as water transfers. The analysis of historical flow records focusses on variability indices (Parde index, Richards-Baker-Flashiness Index, Interquartile Ratio and Baseflow Index). The climate change impact simulations were carried out using a model cascade of (i) the statistical regional model STAR (100 stochastically generated realizations each for 3 scenarios with different prescribed temperature trend), (ii) the hydrological models SWIM and EGMO, and (iii) the water resources management model WBalMo. The analysis of the observed discharges reveals that the annual discharge variability in the Spree catchment is dominated by mining activities rather than natural rainfall-runoff processes. Due to the high reservoir capacity in the Spree catchment its discharge is characterised by less seasonality and short-term variability compared to the Schwarze Elster. Simulations with climate change scenarios assuming increasing temperature and decreasing precipitation result in pronounced reductions of discharge in both catchments. The differences in potential natural discharges between the Schwarze Elster and the Spree catchments as projected by the hydrological models SWIM and EGMO are marginal. The uncertainties related to the climate projection are propagated through the hydrological models. In the Schwarze Elster catchment, the managed discharges simulated by WBalMo are comparable to the potential natural discharges. In the Spree River however, the short-term variability is moderated by water resources management and managed discharge under climate change is less affected by amplification of uncertainties through model chains. The results of the study, which combines the analyses of observed flow records and model-based climate change impact simulations, imply that generally, effective water resources management reducing discharge variability hence also reduces uncertainty related to climate change impacts on river discharge. Catchments with a high storage ratio are thus less vulnerable to changing climate conditions. This underlines the role of water resources management in coping with climate change impacts. Yet, due to decreasing reservoir volumes in drought periods, reservoir management alone cannot compensate strong changes in climate conditions over long time periods.}, language = {en} } @misc{ShahHariRakovecetal., author = {Shah, Jignesh and Hari, Vittal and Rakovec, Oldrich and Markonis, Yannis and Samaniego, Luis and Mishra, Vimal and Hanel, Martin and Hinz, Christoph and Kumar, Rohini}, title = {Increasing footprint of climate warming on flash droughts occurrence in Europe}, series = {Environmental Research Letters}, volume = {17}, journal = {Environmental Research Letters}, number = {6}, issn = {1748-9326}, doi = {10.1088/1748-9326/ac6888}, abstract = {Flash droughts are caused by a rapid depletion of soil moisture, and they severely affect vegetation growth and agricultural production. Notwithstanding the growing importance of flash droughts under the warming climate, drivers of flash droughts across the Europe are not well understood. Here we estimate the changes in flash droughts characteristics across Europe using the ERA5 reanalysis dataset for 1950-2019 period. We find a substantial increase in the frequency and spatial extent of flash droughts across Europe (with 79\% of the total area) during the growing season with at-least one fourth of domain showing two-fold increase in the recent decades. Increased occurrence of flash drought is largely attributed to frequent occurrence of warmer and drier compound extremes, with a sharp gradient of changes being noticed in Mediterranean and Central European regions. Compound meteorological extremes causing the flash drought events across Europe are pre-dominantly driven by the recent climate warming. With unabated greenhouse gas emissions and current pace of climate warming, Europe is likely to face an increased occurrence of flash droughts, requiring prompt response for effective drought adaptation and management strategies.}, language = {en} } @misc{KhoshBinGhomashBachmannCaviedesVoulliemeetal., author = {Khosh Bin Ghomash, Shahin and Bachmann, Daniel and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Introducing a dynamic spatiotemporal rainfall generator for flood risk analysis}, series = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, journal = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, doi = {10.5194/egusphere-egu23-2599}, abstract = {Precipitation scenario analysis is a crucial step in flood risk assessment, in which storm events with different probabilities are defined and used as input for the hydrological/hydrodynamic calculations. Rainfall generators may serve as a basis for the precipitation analysis. With the increase in the use of high resolution spatially-explicit hydrological/hydrodynamic models in flood risk calculations, demand for synthetic gridded precipitation input is increasing. In this work, we present a dynamic spatiotemporal rainfall generator. The model is capable of generating catchment-scale rainfields containing moving storms, which enable physically-plausible and spatiotemporally coherent precipitation events. This is achieved by the tools event-based approach, where dynamic storms are identified as clusters of related data that occur at different locations in space and time, and are then used as basis for event regeneration. The implemented methodology, mainly inspired by Dierden et al. (2019), provides an improvement in the spatial coherence of precipitation extremes, which can in turn be beneficial in flood risk calculations. The model has been validated under different databases such as the radar-based RADALON dataset or spatially-interpolated historical raingauge timeseries of different catchments in Germany, which is also presented in this work. The validation indicates the models ability to adequately preserve observed storm statistics in the generated timeseries. The generator is developed as an extension to the state-of-the-science flood risk modelling tool ProMaIDes (Promaides 2023). The model also puts great focus on user accessibility with offering features such as an easy installation process, support for most operating systems, a user interface and an online user manual.}, language = {en} } @inproceedings{VarraniCaviedesVoulliemeHinz, author = {Varrani, Arianna and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Dynamic mapping of surface topografy at rainfall events}, series = {Proceedings of the 5th IAHR Europe Congress — New Challenges in Hydraulic Research and Engineering}, booktitle = {Proceedings of the 5th IAHR Europe Congress — New Challenges in Hydraulic Research and Engineering}, editor = {Armanini, Aronne and Nucci, Elena}, publisher = {IAHR Secretariat, Department of Civil, Environmental and Mechanical Engineering}, address = {Madrid, Spain}, isbn = {978-981-11-2731-1}, pages = {139 -- 140}, abstract = {Landscape evolution forced by rainfall is simulated at the laboratory scale and dynamically tracked using six virtual sensors Kinect™ to ensure detailed meas-urements with relatively low-cost devices.}, language = {en} } @inproceedings{CaviedesVoulliemeHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {An ecohydrological model to explore topographic and rainfall variability effects on vegetation self-organisation}, series = {Computational Methods in Water Resources XXII (CMWR 2018), Bridging gaps between data, models, and predictions}, booktitle = {Computational Methods in Water Resources XXII (CMWR 2018), Bridging gaps between data, models, and predictions}, pages = {2}, language = {en} } @inproceedings{CaviedesVoulliemeFernandezPatoHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Fern{\´a}ndez-Pato, Javier and Hinz, Christoph}, title = {Zero-Inertia vs full shallow water equations: a comparison for rainfall-runoff modelling}, series = {Computational Methods in Water Resources XXII (CMWR 2018), Bridging gaps between data, models, and predictions}, booktitle = {Computational Methods in Water Resources XXII (CMWR 2018), Bridging gaps between data, models, and predictions}, pages = {2}, language = {en} } @inproceedings{PohleNiebischZhaetal., author = {Pohle, Ina and Niebisch, Michael and Zha, Tingting and Sch{\"u}mberg, Sabine and M{\"u}ller, Hannes and Maurer, Thomas and Hinz, Christoph}, title = {A stochastical event-based continuous time step rainfall generator based on Poisson rectangular pulse and microcanonical random cascade models}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Rainfall variability within a storm is of major importance for fast hydrological processes, e.g. surface runoff, erosion and solute dissipation from surface soils. To investigate and simulate the impacts of within-storm variabilities on these processes, long time series of rainfall with high resolution are required. Yet, observed precipitation records of hourly or higher resolution are in most cases available only for a small number of stations and only for a few years. To obtain long time series of alternating rainfall events and interstorm periods while conserving the statistics of observed rainfall events, the Poisson model can be used. Multiplicative microcanonical random cascades have been widely applied to disaggregate rainfall time series from coarse to fine temporal resolution. We present a new coupling approach of the Poisson rectangular pulse model and the multiplicative microcanonical random cascade model that preserves the characteristics of rainfall events as well as inter-storm periods. In the first step, a Poisson rectangular pulse model is applied to generate discrete rainfall events (duration and mean intensity) and inter-storm periods (duration). The rainfall events are subsequently disaggregated to high-resolution time series (user-specified, e.g. 10 min resolution) by a multiplicative microcanonical random cascade model. One of the challenges of coupling these models is to parameterize the cascade model for the event durations generated by the Poisson model. In fact, the cascade model is best suited to downscale rainfall data with constant time step such as daily precipitation data. Without starting from a fixed time step duration (e.g. daily), the disaggregation of events requires some modifications of the multiplicative microcanonical random cascade model proposed by Olsson (1998): Firstly, the parameterization of the cascade model for events of different durations requires continuous functions for the probabilities of the multiplicative weights, which we implemented through sigmoid functions. Secondly, the branching of the first and last box is constrained to preserve the rainfall event durations generated by the Poisson rectangular pulse model. The event-based continuous time step rainfall generator has been developed and tested using 10 min and hourly rainfall data of four stations in North-Eastern Germany. The model performs well in comparison to observed rainfall in terms of event durations and mean event intensities as well as wet spell and dry spell durations. It is currently being tested using data from other stations across Germany and in different climate zones. Furthermore, the rainfall event generator is being applied in modelling approaches aimed at understanding the impact of rainfall variability on hydrological processes.}, language = {en} } @inproceedings{HinzSchaafGerwinetal., author = {Hinz, Christoph and Schaaf, Wolfgang and Gerwin, Werner and Pohle, Ina}, title = {Entwicklung eines transienten hydrologischen Systems: Zustands{\"a}nderungen des k{\"u}nstlichen Einzugsgebiets H{\"u}hnerwasser}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 1}, language = {de} } @inproceedings{MaurerPohleOeseretal., author = {Maurer, Thomas and Pohle, Ina and Oeser, Anne and Sieber, Andr{\´e} and Hinz, Christoph}, title = {Bestimmung der Zusammenh{\"a}nge zwischen Bestandsniederschlag, meteorologischen Variablen und Vegetationsstruktur in einem sich entwickelnden Einzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 34}, language = {de} } @inproceedings{CaviedesVoulliemeDominHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Domin, Andrea and Hinz, Christoph}, title = {Nonlinear effects of microtopography on macroscopic rainfall-runoff partitioning a the hillslope scale: a modelling study}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The quantitative description and prediction of hydrological response of hillslopes or hillslope-scale catchments to rainfall events is becoming evermore relevant. At the hillslope scale, the onset of runoff and the overall rainfall-runoff transformation are controlled by multiple interacting small-scale processes, that, when acting together produce a response described in terms of hydrological variables well-defined at the catchment and hillslope scales. We hypothesize that small scale features such microtopography of the land surface will will govern large scale signatures of temporal runoff evolution. This can be tested directly by numerical modelling of well-defined surface geometries and adequate process description. It requires a modelling approach consistent with fundamental fluid mechanics, well-designed numerical methods, and computational efficiency. In this work, an idealized rectangular domain representing a hillslope with an idealized 2D sinusoidal microtopography is studied by simulating surface water redistribution by means of a 2D diffusive-wave (zero-inertia) shallow water model. By studying more than 500 surfaces and performing extensive sensitivity analysis forced by a single rainfall pulse, the dependency of characteristic hydrological responses to microtopographical properties was assessed. Despite of the simplicity of periodic surface and the rain event, results indicate complex surface flow dynamics during the onset of runoff observed at the macro and micro scales. Macro scale regimes were defined in terms of characteristics hydrograph shapes and those were related to surface geometry. The reference regime was defined for smooth topography and consisted of a simple hydrograph with smoothly rising and falling limbs with an intermediate steady state. In constrast, rough surface geometry yields stepwise rising limbs and shorter steady states. Furthermore, the increase in total infiltration over the whole domain relative to the smooth reference case shows a strong non-linear dependency on slope and the ratio of the characteristic wavelength and amplitude of microtopography. The coupled analysis of spatial and hydrological results also suggests that the hydrological behaviour can be explained by the spatiotemporal variations triggered by surface connectivity. This study significantly extents previous work on 1D domains, as our results reveal complexities that require 2D representation of the runoff processes.}, language = {en} } @inproceedings{CaviedesVoulliemeJozefikHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Jozefik, Zoltan and Hinz, Christoph}, title = {Towards a physically-based multi-scale ecohydrological simulator for semi-arid regions}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The use of numerical models as tools for describing and understanding complex ecohydrological systems has enabled to test hypothesis and propose fundamental, process-based explanations of the system system behaviour as a whole as well as its internal dynamics. Reaction-diffusion equations have been used to describe and generate organized pattern such as bands, spots, and labyrinths using simple feedback mechanisms and boundary conditions. Alternatively, pattern-matching cellular automaton models have been used to generate vegetation self-organization in arid and semi-arid regions also using simple description of surface hydrological processes. A key question is: How much physical realism is needed in order to adequately capture the pattern formation processes in semi-arid regions while reliably representing the water balance dynamics at the relevant time scales? In fact, redistribution of water by surface runoff at the hillslope scale occurs at temporal resolution of minutes while the vegetation development requires much lower temporal resolution and longer times spans. This generates a fundamental spatio-temporal multi-scale problem to be solved, for which high resolution rainfall and surface topography are required. Accordingly, the objective of this contribution is to provide proof-of-concept that governing processes can be described numerically at those multiple scales. The requirements for a simulating ecohydrological processes and pattern formation with increased physical realism are, amongst others: i. high resolution rainfall that adequately captures the triggers of growth as vegetation dynamics of arid regions respond as pulsed systems. ii. complex, natural topography in order to accurately model drainage patterns, as surface water redistribution is highly sensitive to topographic features. iii. microtopography and hydraulic roughness, as small scale variations do impact on large scale hillslope behaviour iv. moisture dependent infiltration as temporal dynamics of infiltration affects water storage under vegetation and in bare soil Despite the volume of research in this field, fundamental limitations still exist in the models regarding the aforementioned issues. Topography and hydrodynamics have been strongly simplified. Infiltration has been modelled as dependent on depth but independent of soil moisture. Temporal rainfall variability has only been addressed for seasonal rain. Spatial heterogenity of the topography as well as roughness and infiltration properties, has not been fully and explicitly represented. We hypothesize that physical processes must be robustly modelled and the drivers of complexity must be present with as much resolution as possible in order to provide the necessary realism to improve transient simulations, perhaps leading the way to virtual laboratories and, arguably, predictive tools. This work provides a first approach into a model with explicit hydrological processes represented by physicallybased hydrodynamic models, coupled with well-accepted vegetation models. The model aims to enable new possibilities relating to spatiotemporal variability, arbitrary topography and representation of spatial heterogeneity, including sub-daily (in fact, arbitrary) temporal variability of rain as the main forcing of the model, explicit representation of infiltration processes, and various feedback mechanisms between the hydrodynamics and the vegetation. Preliminary testing strongly suggests that the model is viable, has the potential of producing new information of internal dynamics of the system, and allows to successfully aggregate many of the sources of complexity. Initial benchmarking of the model also reveals strengths to be exploited, thus providing an interesting research outlook, as well as weaknesses to be addressed in the immediate future.}, language = {en} } @inproceedings{BrueckSchulteOverbergPohleetal., author = {Br{\"u}ck, Yasemine and Schulte-Overberg, Philipp and Pohle, Ina and Hinz, Christoph}, title = {NDVI (Normalized Difference Vegetation Index) signatures of transient ecohydrological systems: The case of post-mining landscapes}, series = {European Geosciences Union, General Assembly 2017, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2017, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Assessing ecohydrological systems that undergo state transitions due to environmental change is becoming increasingly important. One system that can be used to study severe disturbances are post-mining landscapes as they usually are associated with complete removal of vegetation and afterwards subsequent ecosystem restoration or spontaneous rehabilitation in line with natural succession. Within this context it is of interest, whether and how (fast) the land cover in these areas returns to conditions comparable to those in the undisturbed surrounding or those prior mining. Many aspects of mine site rehabilitation depend on climatic, geomorphic and ecological settings, which determine at which rate vegetation may be reestablished. In order to identify general patterns of vegetation establishment, we propose to use NDVI (Normalized Difference Vegetation Index) time series for mine affected land to estimate rate of recovery across climate regions and ecoregions. In this study we analysed the MODIS Terra Satellite 8 day-composite NDVI for areas influenced by surface mining in different climates from 2001 to 2015. The locations have been chosen based on their extent and the data availability of mining and rehabilitation activities. We selected coal extraction as a case study as strip mining generates well-defined chronosequences of disturbance. The selected mining areas are located in equatorial, arid, warm temperate or snow climates with different precipitation and temperature conditions according to the K{\"o}ppen-Geiger classification. We analysed the NDVI time series regarding significant characteristics of the re-vegetation phase. We applied hierarchical cluster analysis to capture the spatial heterogeneity between different pixels (ca. 250 * 250 m2 each) in and around each open cast mine. We disentangled seasonality, trend and residual components in the NDVI time series by Seasonal and Trend decomposition using LOESS. As expected the time of the removal of vegetation can be clearly identified from the NDVI time series and provides the starting point of disturbance. The cluster analysis allowed us to distinguish between the non-mining land, the mine and the restored land of different ages. Based on these clusters, the time series decomposition revealed the dominance of the trend of increasing NDVI in areas undergoing the restoration process as well as the prevailing seasonality of the oldest restored sites. The determined phase of a dominant trend component, lasting until the NDVI is in the range of the surrounding landscape or the pre-mining conditions, is in the scale of a decade. The impacts of different hydroclimatic regimes and different rehabilitation strategies on long term NDVI development are currently being investigated. Furthermore, coherence analysis will be applied to quantify short term influences of hydrometeorological variables on vegetation development.}, language = {en} } @inproceedings{MaurerBrueckHinzetal., author = {Maurer, Thomas and Br{\"u}ck, Yasemine and Hinz, Christoph and Gerke, Horst H.}, title = {Modeling 3D soil and sediment distributions for assessing catchment structure and hydrological feedbacks}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{BrueckPohleKeuleretal., author = {Br{\"u}ck, Yasemine and Pohle, Ina and Keuler, Klaus and Schaller, Eberhard and Hinz, Christoph}, title = {Do mining lakes in the Lusatian Lignite mining region (Eastern Germany) affect regional precipitation patterns?}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Due to the flooding of former open-pit mines, Europe's largest artificial lake district is created in Eastern Germany. Between 1990 and 2006 more than 80 km² of new lakes have already been formed. These large-scale land cover changes may impact regional meteorological characteristics, therefore it is of interest, whether effects of the mining lakes can already be observed. We especially focus on whether the evaporation from the mining pit lakes leads to a higher precipitation on their lee side. To detect changes in the precipitation patterns, we analysed daily precipitation data (1980-2014) of 25 stations in an area of 10 000 km² widely around the lake district. Under the assumption that the influences of the lakes should be detectable either directly as trends in the observed data or as a deviation from a general measure for precipitation we combined statistical tests and principal component analysis (PCA). We applied pre-whitening Mann-Kendall tests to detect precipitation trends and Mann-Whitney tests to detect differences between split samples (before and after the flooding of most of the lakes). The PCA was applied based on the correlation matrix of daily precipitation at the different stations. As the daily precipitation can sufficiently be explained by the first five principal components, the recombination of these five principal components was used as a general measure of precipitation in the region. By regression trees (random forests) a relation between the eigenvectors of the first five principal components and physiogeographic characteristics of the stations (e.g. altitude) was shown. Both the observed data and the deviations between the measurements and the recombination of the first five principal components showed divergent trends with high spatial variability and also interannual variability, but a pattern consistent with the lee side of the lake could not be detected. Therefore, it has been demonstrated that the emerging lakes had no influence on the daily precipitation at the stations considered in this study. This may be explained by the coarse spatial and also temporal resolution of precipitation measurements. Still, the approach presented here can be applied to (i) detect changes in the spatial pattern of climate variables by a combination of statistical tests and PCA and (ii) to analyse the relationships between such changes and physiogeographic characteristics by regression trees.}, language = {en} } @inproceedings{MaurerTrujilloSiliezarOeseretal., author = {Maurer, Thomas and Trujillo Sili{\´e}zar, Carlos Gustavos and Oeser, Anne and Pohle, Ina and Hinz, Christoph}, title = {A methodology for investigating interdependencies between measured throughfall, meteorological variables and canopy structure on a small catchment}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {In evolving initial landscapes, vegetation development depends on a variety of feedback effects. One of the less understood feedback loops is the interaction between throughfall and plant canopy development. The amount of throughfall is governed by the characteristics of the vegetation canopy, whereas vegetation pattern evolution may in turn depend on the spatio-temporal distribution of throughfall. Meteorological factors that may influence throughfall, while at the same time interacting with the canopy, are e.g. wind speed, wind direction and rainfall intensity. Our objective is to investigate how throughfall, vegetation canopy and meteorological variables interact in an exemplary eco-hydrological system in its initial development phase, in which the canopy is very heterogeneous and rapidly changing. For that purpose, we developed a methodological approach combining field methods, raster image analysis and multivariate statistics. The research area for this study is the H{\"u}hnerwasser ('Chicken Creek') catchment in Lower Lusatia, Brandenburg, Germany, where after eight years of succession, the spatial distribution of plant species is highly heterogeneous, leading to increasingly differentiated throughfall patterns. The constructed 6-ha catchment offers ideal conditions for our study due to the rapidly changing vegetation structure and the availability of complementary monitoring data.Throughfall data were obtained by 50 tipping bucket rain gauges arranged in two transects and connected via a wireless sensor network that cover the predominant vegetation types on the catchment (locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens). The spatial configuration of the vegetation canopy for each measurement site was described via digital image analysis of hemispheric photographs of the canopy using the ArcGIS Spatial Analyst, GapLight and ImageJ software. Meteorological data from two on-site weather stations (wind direction, wind speed, air temperature, air humidity, insolation, soil temperature, precipitation) were provided by the 'Research Platform Chicken Creek'. Data were combined and multivariate statistical analysis (PCA, cluster analysis, regression trees) were conducted using the R-software to i) obtain statistical indices describing the relevant characteristics of the data and ii) to identify the determining factors for throughfall intensity. The methodology is currently tested and results will be presented. Preliminary evaluation of the image analysis approach showed only marginal, systematic deviation of results for the different software tools applied, which makes the developed workflow a viable tool for canopy characterization. Results from this study will have a broad spectrum of possible applications, for instance the development / calibration of rainfall interception models, the incorporation into eco-hydrological models, or to test the fault tolerance of wireless rainfall sensor networks.}, language = {en} } @inproceedings{ZaplataVestePohleetal., author = {Zaplata, Markus Klemens and Veste, Maik and Pohle, Ina and Sch{\"u}mberg, Sabine and Abreu Schonert, Iballa and Hinz, Christoph}, title = {Experimental investigation of the early interaction between cyanobacterial soil crusts and vascular plants}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {While there are hints that biological soil crusts (BSCs) can constitute physical barriers for the emergence of vascular plants, a conceptual approach for the quantitative evaluation of these effects is still missing. Here we present an experimental design to test the emergence of seedlings in situ with (i) capping natural intact, (ii) destroyed and (iii) removed BSC. The selected field site is directly adjacent to the constructed H{\"u}hnerwasser catchment (Lusatia, Germany). This site exists since the end of 2008 and consists of loamy sand. Serving as proxy for seedling thrust, we inserted pre-germinated seeds of three confamiliar plant species with different seed masses (members of the Fabaceae family: Lotus corniculatus L., Ornithopus sativus Brot., and Glycine max (L.) Merr.). In each treatment as well as in the control group planting depths were 10 mm. We took care that experimental plots had identical crust thickness, slightly less than 4 mm, serving as proxy for mechanical resistance. A plot became established as follows: Firstly, the pristine crusted surface was vertically cut. To the windward side the BSC remained intact (i: "with BSC" stripe). To the downwind side soil material was temporarily excavated for laterally inserting the seeds beneath the surface of the first stripe. Then at the thereby disturbed second stripe pulverised BSC material became filled as a top layer (ii: "BSC mix" stripe). From the next stripe the BSC was removed (iii : "no BSC" stripe). Thus each plot had each experimental group in spatial contiguity (within 50 cm * 50 cm). The overall 50 plots were distributed across an area of 40 m * 12 m. When individuals of a species either emerged at all stripes, "XXX", or at no stripe of a plot, "- - -", there was no reason to suppose any effect of a crust. The "-XX" emergence pattern (depicting the appearance of seedlings in both stripes possessing manipulated surfaces) points towards hindrance more clearly than "-X-" or "- - X". Altogether eight possible combinations exist. Combinatorial analysis turned out that seedling emergence had been notably impeded for light-weighted seeds but little for heavy seeds. Repeated recordings enable to account for adaptable emergence of seedlings according to varying crust conditions - in spatial as well as temporal terms. The proposed experimental procedure hence is highly recommended as a viable instrument to further investigate filter and facilitation processes between BSCs and vascular plants.}, language = {en} } @misc{KhoshBinGhomashBachmannCaviedesVoulliemeetal., author = {Khosh Bin Ghomash, Shahin and Bachmann, Daniel and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Effects ofWithin-Storm Variability on Allochthonous Flash Flooding: A Synthetic Study}, series = {Water}, volume = {15}, journal = {Water}, number = {4}, issn = {2073-4441}, doi = {10.3390/w15040645}, abstract = {Rainfall is a spatiotemporally variated process and one of the key elements to accurately capture both catchment runoff response and floodplain extents. Flash floods are the result of intense rainfall, typically associated to highly variable rain in both space and time, such as convective storms. In this work, the extent within-storm variability affects runoff and flooding is explored. The Kan catchment (Tehran, Iran) is used as base topography for the simulations. The allochthonous nature of floods in the catchment and how they interact with the effects of storm variability are further investigated. For this, 300 synthetic rainfall signals with different hyetograph variabilities are generated and imposed on a 1D/2D hydrodynamic model. Additionally, a set of simulations with different levels of spatial variability are performed. The results suggest that temporal and spatial variability affect the runoff response in different degrees. Peak discharge and hydrograph shapes, as well as flooded areas, are affected. The effect of storm temporal variability is shown to be significantly higher than storm spatial variability and storm properties such as return period, duration, and volume. Further on the influence of storm spatiotemporal variability on stream discharge and flood response is seen to be strongly dependent on the location within the drainage network at which it is assessed.}, language = {en} } @misc{KhoshBinGhomashBachmannCaviedesVoulliemeetal., author = {Khosh Bin Ghomash, Shahin and Bachmann, Daniel and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Impact of Rainfall Movement on Flash Flood Response: A Synthetic Study of a Semi-Arid Mountainous Catchment}, series = {Water}, volume = {14}, journal = {Water}, number = {12}, issn = {2073-4441}, doi = {10.3390/w14121844}, abstract = {Rainfall is a spatiotemporally varied process and key to accurately capturing catchment runoff and determining flood response. Flash flood response of a catchment can be strongly governed by a rainfall's spatiotemporal variability and is influenced by storm movement which drives a continuous spatiotemporal change throughout a rainfall event. In this work, the sensitivity of runoff and flooded areas to rainfall movement are assessed in the Kan catchment (Iran). The allochthonous nature of floods in the catchment and how they interact with the effects of rainfall movement are investigated. Fifty synthetic rain hyetographs are generated and traversed over the catchment under different velocities and directions and used to force a 1D/2D hydrodynamic model. The results suggest rainfall movement affects the runoff response in different degrees. Peak discharge, hydrograph shapes and flooded areas are affected. Storms with higher velocities result in higher peaks and faster onsets of runoff and consequently higher flooded areas in comparison to slower storms. The direction of the movement also plays a role. Storms moving along the average direction of the stream result in higher peaks and flooded areas. The relevance of storm direction is greater for slow moving storms. Additionally, the influence of rainfall movement is modulated by hyetograph structure, and the allochthonous behavior is greatly dependent on the location within the drainage network at which it is assessed.}, language = {en} } @misc{KhoshBinGhomashCaviedesVoulliemeHinz, author = {Khosh Bin Ghomash, Shahin and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Effects of erosion-induced changes to topography on runoff dynamics}, series = {Journal of Hydrology}, volume = {573}, journal = {Journal of Hydrology}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2019.04.018}, pages = {811 -- 828}, abstract = {Runoff generation from rainfall events is a complex, spatial and temporally dependent process strongly governed, among other factors, by catchment surface topography. Although it is widely known that many catchments experience morphological evolution, it is often ignored in analysis for different reasons ranging from simplification to lack of data. However, young catchments and early landscapes (such as those which are affected by natural or anthropogenic disturbances) do exhibit topography changes which in turn affect catchment hydrodynamics, hydrology and in particular runoff. In this work, we study the runoff generation and hydrodynamics of the H{\"u}hnerwasser artificial catchment (Brandenburg, Germany) during a period of erosion-based topographical changes (2006-2010). Nine Digital Elevation Models from such period were used as topography over which physically-based simulations were performed. The results suggest that topographic evolution in this catchment mostly affects the onset of runoff, whereas peak discharges and receding hydrograph limbs are less affected. These differences in hydrological signatures can be explained through the changes in the spatial distribution of runoff hydrodynamics and their impact on surface runoff connectivity. Relatively small topographical differences produce changing ponding conditions and modify flowpaths which becomes evident only through inspection of the spatial distribution of hydrodynamic variables. Moreover, the study shows that in order for simulations to be able to capture such responses, appropriate computational mesh and topographical data resolution are critical, since connectivity itself can be greatly affected by low resolution data or representation.}, language = {en} } @misc{SchuettCaviedesVoulliemeHinz, author = {Sch{\"u}tt, Claudia and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Exploring the effects of rainfall variability on banded vegetation}, series = {EGU General Assembly 2020, Online, 4-8 May 2020}, journal = {EGU General Assembly 2020, Online, 4-8 May 2020}, doi = {10.5194/egusphere-egu2020-13238}, language = {en} } @misc{MaurerCaviedesVoulliemeGerkeetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Gerke, Horst H. and Hinz, Christoph}, title = {A 3D-spatial approach for modeling soil hydraulic property distributions on the artificial Huehnerwasser catchment}, series = {Geophysical Research Abstracts}, volume = {21}, journal = {Geophysical Research Abstracts}, pages = {1}, abstract = {Knowledge of catchment 3D spatial heterogeneity is crucial for the assessment and modeling of eco-hydrological processes. Especially during the initial development phase of a hydro-geo-system, the primary structural properties have the potential to determine further development pathways. Small-scale heterogeneity (cm to m scale) may have significant effects on processes on larger spatial scales, but is difficult to measure and quantify. The H{\"u}hnerwasser (Chicken Creek) catchment offers the unique opportunity to study early ecosystem development within an initial structural setup that is well-known, from the plot up to the catchment scale. Based on information on the open-cast mining technology, catchment boundaries and sediment properties, we developed a structure generator program for the process-based modeling of specific dumping structures and sediment property distributions on the catchment. The structure generator reproduces the trajectories of spoil ridges and can be conditioned to reproduce actual sediment distributions according to remote sensing and soil sampling data. Alternatively, sediment distribution scenarios can be generated based on geological data from the excavation site, or can be distributed stochastically. Using pedotransfer functions, the effective hydraulic van-Genuchten parameters are then calculated from sediment texture and bulk density. The main application of the 3D catchment model is to provide detailed 3D-distributed flow domain information for hydrological flow modeling. Observation data are available from catchment monitoring are available for determining the boundary conditions (e.g., precipitation), and the calibration / validation of the model (catchment discharge, ground water). The analysis of multiple sediment distribution scenarios allows to evaluate the effect of initial conditions on hydrological behavior development. Generally, the modeling approach can be used to pinpoint the influx of specific soil structural features on ecohydrological processes across spatial scales.}, language = {en} } @misc{CaviedesVoulliemeFernandezPatoHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Fern{\´a}ndez-Pato, Javier and Hinz, Christoph}, title = {Cellular Automata and Finite Volume solvers converge for 2D shallow flow modelling for hydrological modelling}, series = {Journal of Hydrology}, volume = {563}, journal = {Journal of Hydrology}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2018.06.021}, pages = {411 -- 417}, abstract = {Surface flows of hydrological interest, including overland flow, runoff, river and channel flow and flooding have received significant attention from modellers in the past 30 years. A growing effort to address these complex environmental problems is in place in the scientific community. Researchers have stud-ied and favoured a plethora of techniques to approach this issue, ranging from very simple empirically-based mathematical models, to physically-based, deductive and very formal numerical integration of systems of partial-differential equations. In this work, we review two families of methods: cell-based simulators - later called Cellular Automata - and Finite Volume solvers for the Zero-Inertia equation, which we show to converge into a single methodology given appropriate choices. Furthermore, this convergence, mathematically shown in this work, can also be identified by critically reviewing the exist-ing literature, which leads to the conclusion that two methods originating from different reasoning and fundamental philosophy, fundamentally converge into the same method. Moreover, acknowledging such convergence allows for some generalisation of properties of numerical schemes such as error behaviour and stability, which, importantly, is the same for the converging methodology, a fact with practical implications. Both the review of existing literature and reasoning in this work attempts to aid in the effort of synchronising and cross-fertilizing efforts to improve the understanding and the outlook of Zero-Inertia solvers for surface flows, as well as to help in clarifying the possible confusion and parallel develop-ments that may arise from the use of different terminology originating from historical reasons. Moreover, synchronising and unifying this knowledge-base can help clarify model capabilities, applicability and modelling issues for hydrological modellers, specially for those not deeply familiar with the mathematical and numerical details.}, language = {en} } @misc{PohleNiebischMuelleretal., author = {Pohle, Ina and Niebisch, Michael and M{\"u}ller, Hannes and Sch{\"u}mberg, Sabine and Zha, Tingting and Maurer, Thomas and Hinz, Christoph}, title = {Coupling Poisson rectangular pulse and multiplicative microcanonical random cascade models to generate subdaily precipitation time series}, series = {Journal of Hydrology}, volume = {562}, journal = {Journal of Hydrology}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2018.04.063}, pages = {50 -- 70}, abstract = {To simulate the impacts of within-storm rainfall variabilities on fast hydrological processes, long precipi-tation time series with high temporal resolution are required. Due to limited availability of observed data such time series are typically obtained from stochastic models. However, most existing rainfall models are limited in their ability to conserve rainfall event statistics which are relevant for hydrological pro-cesses. Poisson rectangular pulse models are widely applied to generate long time series of alternating precipitation events durations and mean intensities as well as interstorm period durations. Multiplicative microcanonical random cascade (MRC) models are used to disaggregate precipitation time series from coarse to fine temporal resolution. To overcome the inconsistencies between the temporal structure of the Poisson rectangular pulse model and the MRC model, we developed a new coupling approach by introducing two modifications to the MRC model. These modifications comprise (a) a modified cascade model ("constrained cascade") which preserves the event durations generated by the Poisson rectangular model by constraining the first and last interval of a precipitation event to contain precipitation and (b) continuous sigmoid func-tions of the multiplicative weights to consider the scale-dependency in the disaggregation of precipita-tion events of different durations. The constrained cascade model was evaluated in its ability to dis-aggregate observed precipitation events in comparison to existing MRC models. For that, we used a 20-year record of hourly precipitation at six stations across Germany. The constrained cascade model showed a pronounced better agreement with the observed data in terms of both the temporal pattern of the precipitation time series (e.g. the dry and wet spell durations and autocorrelations) and event char-acteristics (e.g. intra-event intermittency and intensity fluctuation within events). The constrained cas-cade model also slightly outperformed the other MRC models with respect to the intensity-frequency relationship. To assess the performance of the coupled Poisson rectangular pulse and constrained cascade model, precipitation events were stochastically generated by the Poisson rectangular pulse model and then disaggregated by the constrained cascade model. We found that the coupled model performs satisfac-torily in terms of the temporal pattern of the precipitation time series, event characteristics and the in-tensity-frequency relationship.}, language = {en} } @inproceedings{Hinz, author = {Hinz, Christoph}, title = {Competing feedbacks as a driver for ecosystems development and restoration success}, series = {5th World Conference on Ecological Restoration, Book of Abstracts, October 6-11, 2013, Madison, Wisconsin, USA}, booktitle = {5th World Conference on Ecological Restoration, Book of Abstracts, October 6-11, 2013, Madison, Wisconsin, USA}, publisher = {Society for Ecological Restoration}, address = {Washington, DC}, pages = {86 -- 87}, language = {en} } @misc{ColettiHinzVogwilletal., author = {Coletti, Janaine Z. and Hinz, Christoph and Vogwill, Ryan and Hipsey, Matthew R.}, title = {Hydrological controls on carbon metabolism in wetlands}, series = {Ecological Modelling}, volume = {249}, journal = {Ecological Modelling}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2012.07.010}, pages = {3 -- 18}, abstract = {Governed by a series of non-linear feedback mechanisms among water, vegetation and decomposers, carbon storage within wetlands is important on a global scale. However, the effect that climatic fluctuations have on those mechanisms is not well documented. In this study, we introduce a mechanistic model connecting hydrology, vegetation and microbial biomass to investigate how changes in the climate signal propagate through wetland ecosystems, via vegetation and microbial dynamics, and attempt to quantify how net rates of wetland carbon metabolism change in response to a changing climate. Our particular focus is the dryland-wetland systems found in south-west Western Australia (SWWA), as they are expected to be sensitive to projected climatic changes due to their close linkage to the seasonal water delivery pattern. The model simulations investigate wetland carbon retention under different hydro-climatological conditions ranging across a regional gradient in the dryness index. The results indicate that short term and long term vegetation responses may be counter-intuitive due to adaptability in the water uptake strategy of the vegetation community partially decoupling biomass from water availability. Furthermore, changes in water delivery are not a good indicator for overall changes in wetland metabolism, defined as the net rate of carbon assimilation, due to the dominance of the soil carbon storages and their sensitivity to heightened bacterial metabolism rates with increasing temperatures. The results highlight that an optimum combination of water supply and vegetation leads to a higher percentage of carbon being stored in soils, therefore increasing the resistance of the carbon storage to changes in precipitation. The model presented here provides a first step to explain how changing patterns of rainfall, temperature and evapotranspiration can change carbon cycling characteristics and the carbon retention efficiency of dryland-wetlands.}, language = {en} } @misc{McGrathNieDyskinetal., author = {McGrath, Gavan S. and Nie, Zhengyao and Dyskin, Arcady and Byrd, Tia and Jenner, Rowan and Holbeche, Georgina and Hinz, Christoph}, title = {In situ fragmentation and rock particle sorting on arid hills}, series = {Journal of Geophysical Research: Earth Surface}, volume = {118}, journal = {Journal of Geophysical Research: Earth Surface}, number = {1}, issn = {2169-9011}, doi = {10.1029/2012JF002402}, pages = {17 -- 28}, abstract = {Transport processes are often proposed to explain the sorting of rock particles on arid hillslopes, where mean rock particle size often decreases in the downslope direction. Here we show that in situ fragmentation of rock particles can also produce similar patterns. A total of 93,414 rock particles were digitized from 880 photographs of the surface of three mesa hills in the Great Sandy Desert, Australia. Rock particles were characterized by the projected Feret's diameter and circularity. Distance from the duricrust cap was found to be a more robust explanatory variable for diameter than the local hillslope gradient. Mean diameter decreased exponentially downslope, while the fractional area covered by rock particles decreased linearly. Rock particle diameters were distributed lognormally, with both the location and scale parameters decreasing approximately linearly downslope. Rock particle circularity distributions showed little change; only a slight shift in the mode to more circular particles was noted to occur downslope. A dynamic fragmentation model was used to assess whether in situ weathering alone could reproduce the observed downslope fining of diameters. Modeled and observed size distributions agreed well and both displayed a preferential loss of relatively large rock particles and an apparent approach to a terminal size distribution of the rocks downslope. We show this is consistent with a size effect in material strength, where large rocks are more susceptible to fatigue failure under stress than smaller rocks. In situ fragmentation therefore produces qualitatively similar patterns to those that would be expected to arise from selective transport.}, language = {en} } @inproceedings{MaurerSchappBuechneretal., author = {Maurer, Thomas and Schapp, Andrea and B{\"u}chner, Steffen and Menzel, Hannes and Hinz, Christoph}, title = {Measurement of rainfall distribution on a small catchment for the evaluation of canopy interception effects}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Variability of rainfall and throughfall is an essential characteristic of the water balance at spatial scales ranging from meters to hundreds of meters or even kilometers. The amount of throughfall is governed by the characteristics of the vegetation canopy and the involved interception and stemflow effects. In initial, developing ecosystems, distinct patterns of the growing vegetation (e.g. patchiness) supposedly govern the spatial distribution of water in the system, thereby initiating and supporting hydro-ecological feedback processes. Questions are i) is the spatial variability of vegetation relevant for the system as a whole, and ii) how does the distribution of the effective precipitation (i.e. the infiltration) change over time in dependency of vegetation succession? We present the first results of a spatially distributed measurement approach of surface-near precipitation on the constructed catchment "H{\"u}hnerwasser" ("Chicken Creek"). The 6-ha site is located in the recultivation area of the lignite open-cast mine "Welzow-S{\"u}d" in Lower Lusatia, Brandenburg, Germany. Here, the free development of an initial ecosystem is investigated since September 2005. After eight years of succession, the spatial distribution of plant species is highly heterogeneous, and gains increasing influence on throughfall patterns, thus impacting the distribution of soil humidity and possibly even surface runoff. For spatially distributed precipitation measurement, 47 tipping bucket rain gauges were installed in heights of 0.5 m and 1.0 m along two transects on the catchment. Rain gauge data were collected by a wireless sensor node network provided by the Sens4U joint research project. The transects run NW-SE and NE-SW and cover the range of plant communities presently existing in the ecosystem: locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens. The raw measurement data were temporally aggregated using a VBA script in order to characterize interception for various types of precipitation events on different time scales. First results from the measurement period 17th July - 3rd September 2013 widely exhibit a good accordance with reference data from on-site weather stations for sites on open ground, while canopy sites show more heterogeneous values, either due to interception or due to canopy collection effects. However, it was found that the explanation of the differences between comparable sites requires an additional inclusion of other relevant parameters, e.g. wind speed and direction, screening effects, and specific canopy characteristics. Moreover, extreme precipitation events sometimes seemed to lead to incorrect measurements either by the sensor and / or node, which required supplementary quality controls of equipment and data. Results from future long-term measurements on the "H{\"u}hnerwasser" catchment will be used to identify possible plant-soil feedback mechanisms and to parameterize models that simulate the behavior of initial eco-hydrological systems}, language = {de} } @inproceedings{HinzSchuembergKubitzetal., author = {Hinz, Christoph and Sch{\"u}mberg, Sabine and Kubitz, Anita and Frank, Franzi and Cheng, Zhang and Frechen, Tobias Nanu and Pohle, Ina}, title = {Dynamic effects of wet-dry cycles and crust formation on the saturated hydraulic conductivity of surface soils in the constructed H{\"u}hnerwasser ("Chicken Creek") catchment}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Highly disturbed soils and substrates used in land rehabilitation undergo rapid changes after the first wetting events which in turn can lead to ecosystem degradation. Such changes were detected during the early development of the constructed H{\"u}hnerwasser ("Chicken Creek") catchment in Lusatia, Germany. Surface substrates consisting of quaternary sandy sediments formed surface seals during the first rainfall events leading to reduced infiltration and substantially increased surface runoff. Subsequently biological soil crusts formed and stabilised the surface. The aim of this study is to investigate the factors that cause the hydraulic conductivity to decrease using undisturbed and disturbed soil samples. Based on the hypothesis that physical and biological crusts lower the hydraulic conductivity, the first set of experiments with undisturbed soil cores from the H{\"u}hnerwasser catchment were carried out to measure the saturated hydraulic conductivity using the constant head method. Measurements were done with intact cores and repeated after the surface crust was removed. As the quaternary glacial sediments tend to display hard setting behaviour, we further hypothesised that the mobilisation of fine particles within the cores lead to pore clogging and that wet-dry cycles will therefore decrease hydraulic conductivity. A second set of experiments using the same methodology consisted of five repeated measurements of hydraulic conductivity after each drying cycle. These measurements were done with undisturbed core samples as well as repacked cores in order to assess how dry packing affects the dynamics of the hydraulic conductivity somewhat similar to the situation during the first wetting after completion of the catchment construction. For all experiments, the temporal evolution of hydraulic conductivity was measured and the turbidity of the effluent was recorded. The results clearly demonstrated that the substrate is highly unstable. The first set of experiments showed that the removal of the crust lead generally to a decrease in hydraulic conductivity. The process of crust removal represented a severe disturbance of the surface soil which to our understanding causes particle mobilisation and subsequent pore clogging. The first hypothesis could neither be rejected nor accepted. The second set of experiments showed that the hydraulic conductivity significantly dropped in particular after the first drying event. This was observed for both undisturbed and repacked samples. The following drying cycles further decreased the hydraulic conductivity in the repacked samples. The decrease in hydraulic conductivity was positively correlated to turbidity values in the effluent of the samples, indicating particle mobilisation in all samples. The results imply that hydraulic properties in such substrates undergo rapid changes that depend on the temporal dynamics of atmospheric drivers, precipitation and evaporative demand, controlling the degree of wetness and the rate and degree of drying during the very early stage after placement. Associated with the dynamics of the atmospheric drivers are the biological changes due to the formation of biological soil crusts and the establishment of vegetation, both of them contributing to the stabilisation of hydraulic properties.}, language = {en} } @misc{CaviedesVoulliemeAhmadiniaHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Ahmadinia, Ebrahim and Hinz, Christoph}, title = {Interactions of Microtopography, Slope and Infiltration Cause Complex Rainfall-Runoff Behavior at the Hillslope Scale for Single Rainfall Events}, series = {Water Resources Research}, volume = {57}, journal = {Water Resources Research}, number = {7}, issn = {1944-7973}, doi = {10.1029/2020WR028127}, pages = {20}, abstract = {Microtopography (MT) can govern runoff dynamics as a net result of local heterogeneities in the flow paths and ponding. This in turn controls the development of the surface water layer that connects and flows downslope. It is therefore important to understand which microtopographic features affect runoff generation dynamics and its macroscopic—hillslope scale—hydrological signatures (e.g., hydrographs, runoff and infiltration volumes). In this study, we numerically solve 2D overland flow from a single rain pulse on 1,460 idealized hillslopes with different slopes and sinusoidal microtopographies and different infiltration capacities. We assess hydrodynamic distributions, hydrographs and hydrological indices to assess the effects of MT and infiltration on the (local) hydrodynamic and (larger scale) hydrologic responses in terms of surface runoff regimes. The results show that MT enhances infiltration and that infiltration and runoff depend in a strong non-linear way on slope and the properties of MT. Three regimes of influence of MT were identified: one in which MT plays a negligible role but there is a high sensitivity to the infiltration capacity curve, a second regime in which hydrological partitioning is highly sensitive to MT and the infiltration capacity curve, and a third regime in which MT increases infiltration, but the response is insensitive to particular features, and more affected by the average slopes. The regimes are the product of the interplay between small (MT) and large scale (slope) properties. Furthermore, the results suggest that hydrological signatures can be interpreted and explained by the spatiotemporal variation of surface connectivity.}, language = {en} } @misc{KhoshBinGhomashBachmannCaviedesVoulliemeetal., author = {Khosh Bin Ghomash, Shahin and Bachmann, Daniel and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Storm movement effects on the flash flood response of the Kan catchment}, series = {EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022}, doi = {10.5194/egusphere-egu22-2494}, abstract = {Rainfall is a complex, spatial and temporally variated process and one of the core inputs for hydrological and hydrodynamic modelling. Most rainfalls are known to be moving storms with varying directions and velocities. Storm movement is known to be an important influence on runoff generation, both affecting peak discharge and the shape of hydrographs. Therefore, exploring the extent rainfall dynamics affect runoff generation and consequently flooded areas, can be an asset in effective flood risk management. In this work, we study how storm movement (e.g. characterized by velocity and direction) can affect surface flow generation, water levels and flooded areas within a catchment. Moreover, the influence of rainfall temporal variability in correlation with storm movement is taken into account. This is achieved by means of numerical-based, spatially explicit surface flow simulations using the tool ProMaIDes (2021), a free software for risk-based evaluation of flood risk mitigation measures. The storm events are generated using a microcanonical random cascade model and further on trajected across the catchment area. The study area is the Kan river catchment located in the province of Tehran (Iran) with a total area of 836 km², which has experienced multiple flooding events in recent years. Due to its semi-arid climate, steep topography with narrow valleys, this area has high potential for flash flood occurrence as a result of high intensity precipitation. The results of this study show a range of possible magnitudes of influence of rainfall movement on the catchment´s runoff response. The resulting flood maps highlight the importance of rainfall velocity and most importantly the direction of the movement in the estimation of flood events as well as their likelihood in catchment area. Moreover, its shown that the magnitude of influence of storm velocity and direction on discharge strongly depends on the location within the river network which it is measured.}, language = {en} } @misc{HinzMengsuwanCaviedesVoullieme, author = {Hinz, Christoph and Mengsuwan, Konlavach and Caviedes-Voullieme, Daniel}, title = {Spatial analytics of self-organized vegetation pattern in semi-arid regions: an example on tiger-bush patterns in Sudan}, series = {EGU General Assembly 2021}, journal = {EGU General Assembly 2021}, doi = {10.5194/egusphere-egu21-10102}, language = {en} } @misc{CaviedesVoulliemeOezgenXianHinz, author = {Caviedes-Voulli{\`e}me, Daniel and {\"O}zgen-Xian, Ilhan and Hinz, Christoph}, title = {Surface runoff connectivity across scales: revisiting three simulation studies}, series = {EGU General Assembly 2021}, journal = {EGU General Assembly 2021}, doi = {10.5194/egusphere-egu21-5004}, language = {en} } @misc{MuellerSchalkHildebrandtetal., author = {M{\"u}ller, Eva Nora and Schalk, Loes von and Hildebrandt, Anke and Hinz, Christoph}, title = {Wasserforschung vor neuen Herausforderungen: {\"O}kohydrologisches Monitoring und Verfahrensentwicklung von innovativen Feldmethoden an terrestrischen und aquatischen Schnittstellen : Positionspapier des Open Space Workshops der 6. Water Research Horizon Conference, 17.-18. Juni 2015, Berlin}, series = {Hydrologie und Wasserbewirtschaftung}, volume = {59}, journal = {Hydrologie und Wasserbewirtschaftung}, number = {6}, issn = {1439-1783}, pages = {431 -- 432}, language = {de} } @misc{PohleKochGaedekeetal., author = {Pohle, Ina and Koch, Hagen and G{\"a}deke, Anne and Hinz, Christoph and Gr{\"u}newald, Uwe}, title = {Does water management reduce the uncertainty of projected climate change impacts on river discharge?}, publisher = {AGU Fall Meeting}, address = {San Francisco}, language = {en} } @misc{GwenziHinzBlebyetal., author = {Gwenzi, Willis and Hinz, Christoph and Bleby, Timothy M. and Veneklaas, Erik J.}, title = {Transpiration and water relations of evergreen shrub species on an artificial landform for mine waste storage versus an adjacent natural site in semi-arid Western Australia}, series = {Ecohydrology}, volume = {7}, journal = {Ecohydrology}, number = {3}, issn = {1936-0592}, doi = {10.1002/eco.1422}, pages = {965 -- 981}, abstract = {In water-limited environments, transpiration may minimize deep drainage on engi-neered covers used for hazardous waste disposal. However, comparative studies investigating plant ecophysiology and water use on engineered covers and natural sites are limited. Water use patterns and plant-water relations of evergreen shrubs were monitored in semi-arid Western Australia to (1) investigate the response of plant-water relations and shrub transpiration to soil moisture changes and (2) quan-tify stand transpiration and its contribution to the water balance. The shrubs showed conservative (<20 cm hr-1) but persistent transpiration. Differential response to rainfall pulses was evident among species; sap velocity for Acacia bivenosa and Acacia inaequilatera increased by 20-103\% (p < 0•05) after rainfall events ex-ceeding 15 mm but declined rapidly to pre-storm levels. On the contrary, sap veloc-ity for Acacia pruinocarpa increased by 61\% after large pulse (83 and 127 mm) as-sociated with cyclonic activity and remained high (10-15 cm hr-1) thereafter. These transpiration patterns suggested contrasting rooting patterns among the spe-cies. Sap velocity was low (<20 mm hr-1) for all species, even when moisture was readily available. Annual shrub transpiration was 65 (engineered cover) and 81 mm (natural shrubland), accounting for 16 and 20\% of annual rainfall (395 mm). Stand characteristics, plant ecophysiology and shrub transpiration were comparable for both sites, demonstrating the importance of using topsoil as a growth medium and seedbank in revegetation. Overall, the study provided insights on ecophysiological behaviour of artificial landforms, and the first empirical evidence suggesting rapid and successful restoration of mined lands can be achieved under semi-arid conditions.}, language = {en} } @misc{GwenziVeneklaasBlebyetal., author = {Gwenzi, Willis and Veneklaas, Erik J. and Bleby, Timothy M. and Yunusa, Isa A.M. and Hinz, Christoph}, title = {Transpiration and plant water relations of evergreen woody vegetation on a recently constructed artificial ecosystem under seasonally dry conditions in Western Australia}, series = {Hydrological Processes}, volume = {26}, journal = {Hydrological Processes}, number = {21}, issn = {1099-1085}, doi = {10.1002/hyp.8330}, pages = {3281 -- 3292}, abstract = {Understanding transpiration and plant physiological responses to environmental conditions is crucial for the design and management of vegetated engineered covers. Engineered covers rely on sustained transpiration to reduce the risk of deep drainage into potentially hazardous wastes, thereby minimizing contamination of water resources. This study quantified temporal trends of plant water potential (ψp), stomatal conductance (gs), and transpiration in a 4-year-old evergreen woody vegetation growing on an artificial sandy substrate at a mine waste disposal facility. Transpiration averaged 0.7 mm day-1 in winter, when rainfall was frequent, but declined to 0.2 mm day-1 in the dry summer, when the plants were quite stressed. In winter, the mean ψp was -0.6 MPa at predawn and -1.5 MPa at midday, which were much higher than the corresponding summer values of -2.0 MPa and -4.8 MPa, respectively. The gs was also higher in winter (72.1-95.0 mmol m-2 s-1) than in summer (<30 mmol m-2 s-1), and negatively correlated with ψp (p < 0.05, r2 = 0.71-0.75), indicating strong stomatal control of transpiration in response to moisture stress. Total annual transpiration (147.2 mm) accounted for only 22\% of the annual rainfall (673 mm), compared with 77\% to 99\% for woody vegetation in Western Australia. The low annual transpiration was attributed to the collective effects of a sparse and young vegetation, low moisture retention of the sandy substrate, and a superficial root system constrained by high subsoil pH. Amending the substrate with fine-textured materials should improve water storage of the substrate and enhance canopy growth and deep rooting, while further reducing the risk of deep drainage during the early stages of vegetation establishment and in the long term. Overall, this study highlights the need to understand substrate properties, vegetation characteristics, and rainfall patterns when designing artificial ecosystems to achieve specific hydrological functions. Copyright © 2011 John Wiley \& Sons, Ltd.}, language = {en} } @misc{McGrathPaikHinz, author = {McGrath, Gavan S. and Paik, Kyungrock and Hinz, Christoph}, title = {Microtopography alters self-organized vegetation patterns in water-limited ecosystems}, series = {Journal of Geophysical Research}, volume = {117}, journal = {Journal of Geophysical Research}, number = {G03021}, issn = {0148-0227}, doi = {10.1029/2011JG001870}, pages = {1 -- 19}, abstract = {In terrestrial systems limited by water availability the spatial distribution of vegetation can self-organize into a mosaic of vegetated patches and bare soil. Spatially extensive competition for water and short-range facilitation underpin many models that describe the process of vegetation pattern formation. Earlier studies investigating this self-organized patchiness have largely considered smooth landscapes. However, topographic variations can significantly alter the redistribution of surface water flow and therefore the pattern-forming process. Here, we consider how microtopographic variations, at the scale of individual plants, alters self-organized vegetation patterns with the use of a simple ecohydrological model. We show that increasing microtopography can induce a change from banded vegetation, oriented across the slope, to irregular drainage patterns, oriented in the downslope direction. The mechanism responsible is shown to be a change in the spatial redistribution of infiltration around plants and plant patches. Only small increases in microtopography are required to cause banded systems with weak facilitation to change to downslope-oriented patterns. When non-periodic boundary conditions were considered, band orientation tended to become oblique to the topographic contour and in some circumstances their migration upslope ceased. These results suggest that diffusive sediment transport processes may be essential for the maintenance of regular periodic vegetation patterns, which implies that erosion may be critical for understanding the susceptibility of these ecosystems to catastrophic shifts.}, language = {en} } @misc{DjajadiHinz, author = {Djajadi, Lynette K. Abbott and Hinz, Christoph}, title = {Synergistic impacts of clay and organic matter on structural and biological properties of a sandy soil}, series = {Geoderma}, volume = {183-184}, journal = {Geoderma}, issn = {0016-7061}, doi = {10.1016/j.geoderma.2012.03.012}, pages = {19 -- 24}, abstract = {Clay and organic matter, when incorporated together in a sandy soil, improved soil aggregation in association with both microbial activity and soil strength. Incorporation of clay into sandy agricultural soils in south-western Australia is a practice used to overcome water repellence, but the addition of high levels of clay can cause hardsetting. We investigated the extent to which addition of clay and organic matter would improve aggregate stability of a sandy agricultural soil from Meckering, Western Australia without negatively affecting soil strength. Four levels of subsoil clay and three levels of lucerne hay were compared in topsoil incubated for up to 42 days at two temperatures. Addition of both clay and lucerne hay together increased stable aggregation and the longer the period of incubation, the greater the macroaggregate stability. A decrease in soil respiration associated with increasing level of clay added may be related to protection of organic matter. Soil strength increased when the amount of clay alone was increased, but addition of both clay and organic matter decreased soil strength. Soil amelioration with 5\% clay and 0.8\% organic matter was most effective at improving the stability of macroaggregates without hardsetting. The non-linear relationships observed demonstrate the importance of understanding interactions between biological and physical components of soil fertility in relation to the sustainability of land management practices.}, language = {en} } @misc{CaviedesVoulliemeFernandezPatoHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Fern{\´a}ndez-Pato, Javier and Hinz, Christoph}, title = {Performance assessment of 2D Zero-Inertia and Shallow Water models for simulating rainfall-runoff processes}, series = {Journal of Hydrology}, volume = {584}, journal = {Journal of Hydrology}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2020.124663}, pages = {20}, abstract = {Rainfall-runoff simulations are increasingly being performed with physically-based and spatially distributed solvers. The current computational and numerical technology enables the use of full shallow water equations solvers to be applied for these type of flow problems. Nonetheless, Zero-Inertia (diffusive wave) solvers have been historically favoured due to their conceptual and mathematical simplicity in comparison to shallow water solvers, with the working assumption that the simplifications introduced by Zero-Inertia will have some assumable impact on accuracy but will also allow for computational efficiency. Since both types of solvers have been primarily developed, benchmarked and compared to each other for fluvial and floodplain simulations, it is relevant to assess t-he relative performance for rainfall-runoff problems. In this work, both solvers are applied to a set of six well known test cases with reference solutions. The performance of the solvers is assessed in terms of global signatures such as hydrographs and flooded areas, but also in terms of spatial distributions of depth and velocity, as well as computational cost. Furthermore, the comparisons are performed across different spatial resolutions. The results show that for rainfall-runoff problems explicit, finite volumes solvers for both equations provide a similar accuracy, but the shallow water solver requires less computational time. The Zero-Inertia solver was found to be less sensitive to mesh refining than the full shallow water solver.}, language = {en} } @misc{CaviedesVoulliemeHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {From nonequilibrium initial conditions to steady dryland vegetation patterns: How trajectories matter}, series = {Ecohydrology}, volume = {13}, journal = {Ecohydrology}, number = {3}, issn = {1936-0584}, doi = {10.1002/eco.2199}, pages = {14}, abstract = {The multiscale nature of ecohydrological processes and feedbacks implies that vegetation patterns arising in water-limited systems are directly linked to water redistribution processes occurring at much shorter timescales than vegetation growth. This in turn suggests that the initially available water in the system can play a role in determining the trajectory of the system, together with the well-known role of the rainfall gradient. This work explores the role of initial hydrological conditions on vegetation dynamics and vegetation patterns. To do so, the HilleRisLambers-Rietkerk model was solved with different rainfall amounts and a large range of initial hydrological conditions spanning from near-equilibrium to far-from-equilibrium conditions. The resulting vegetation patterns and ecohydrological signatures were quantitatively studied. The results show that not only do initial hydrological conditions play a role in the ecohydrological dynamics but also they can play a dominating one even resulting in divergent vegetation patterns that exhibit convergent mean-field properties, including a new set of hybrid patterns. Our results highlight the relevance of assessing both global ecological and hydrological signatures and quantitatively assessing patterns to describe and understand system dynamics and in particular to determine if the systems are transient or steady. Furthermore, our analysis shows that the trajectories the system follows during its transient stages cannot be neglected to understand complex dependencies of the long-term steady state to environmental factors and drivers.}, language = {en} } @misc{AhmadiniaCaviedesVoulliemeHinz, author = {Ahmadinia, Ebrahim and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Coupled effects of microtopography and time-dependant infiltration capacity on rainfall-runoff-infiltration partitioning on a hillslope}, series = {EGU General Assembly 2020, Online, 4-8 May 2020}, journal = {EGU General Assembly 2020, Online, 4-8 May 2020}, doi = {10.5194/egusphere-egu2020-18200}, language = {en} } @misc{RojasCaviedesVoulliemeHinz, author = {Rojas, Pedro and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Semi-automatic image analysis of spatiotemporal vegetation evolution in the H{\"u}hnerwasser catchment}, series = {EGU General Assembly 2020, Online, 4-8 May 2020}, journal = {EGU General Assembly 2020, Online, 4-8 May 2020}, doi = {10.5194/egusphere-egu2020-13522}, language = {en} } @misc{CaviedesVoulliemeHinz, author = {Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Transient trajectories in vegetation patterns spawning from non-equilibrium initial conditions and singular perturbations}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, abstract = {Vegetation self-organisation in water-limited ecosystems in semi-arid climates has been extensively studied by means of numerical simulation using a set of different reaction-diffusion-equations. Most of such models and studies have been concerned with the long-term steady ecohydrological steady states on domains with periodic boundary conditions and forced by steady rainfall. A vast majority of the modelling literature on vegetation self-organisation exists around near-equilibrium conditions. One of the clearest examples of this is that most of the published numerical results have been obtained by evolving near-equilibrium initial conditions to asymptotic steady states, since researchers have been historically interested in the resilience and stability of the systems to perturbation around converged, steady (equilibrium) states and little interest has been given to the transient states which lead to the equilibrium states. Nonetheless, ecohydrological theory recognises that dryland ecosystems can often be far-from-equilibrium systems, in quasi-permanent transient condition, exhibiting non-linear responses to boundary conditions and forcings. This prompts the question of how different the behaviour of the system can be when far-from equilibrium. In this contribution we explore the role of far-from equilibrium initial hydrological conditions on both the transient and long-term asymptotically steady ecohydrological states. A simulation study was performed using the HilleRisLambers-Rietkerk ecohydrological model on a flatland varying the initial available water both near and far from equilibrium whilst also spanning the rainfall gradient (90 - 360 mm/year), performing simulations up to 200 years long. The results were assessed in terms of the evolution of total biomass yield and hydrological water balance, as well as a quantitative assessment of vegetation patterns. The results show that equilibrium conditions always yield smooth system trajectories, with little over- or undershooting, converging to the well-established patterns in the literature. However, as initial conditions move further away from equilibrium, the patterns start to differ, both in their temporal trajectory as in their long-term stable states. Conditions closer to equilibrium generate patterns with quantitative differences when compared to equilibrium conditions (e.g., larger spots). Conditions far from equilibrium can result in an entirely different hybrid patterns, consisting of a mix of spots, arcs and spirals. We evaluate these differences both qualitatively (by observing the patterns) and quantitatively, through a set of geometric indicators which describe the patterns. The results show that the patterns are history dependent and suggest that published results so far are only a subset of possible patterns. Additionally, the quantitative assessment of pattern properties in time shows that although patterns appear steady, they may indeed be slowly changing over time, while the total biomass and vegetation cover are steady early on. This has implications on the definitions of ecohydrological steady states. We also show that the effects of the idealised initial conditions on model results can be analogous to singular hydrometeorological events, as even stable patterns can be shifted into hybrid patterns by single events. Furthermore, we also explore how the new hybrid patterns compare to the well-established ones in terms of resilience to hydrological perturbations.}, language = {en} } @misc{KhoshBinGhomashCaviedesVoulliemeHinz, author = {Khosh Bin Ghomash, Shahin and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Effects of topography and infiltration heterogeneity on surface runoff and connectivity in the Huehnerwasser catchment}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, abstract = {The Huehnerwasser catchment is a monitored, early-development constructed catchment within the Lower Lausatia post-mining landscape in Germany. From the initial bare catchment state, a sequence of landscape-forming processes occurred, including erosion-based topographic change and vegetation establishment, which are at the centre of this study. Erosion-based topographic change is strongly driven by surface runoff, while in turn itself also modifying runoff in the catchment. These topographic changes can have a significant impact on the hydrological response of a catchment, as they can affect flow paths, flow speeds and rainfall-runoff-infiltration partitioning, all of which manifest in different ways in runoff hydrographs in response to rainfall events. Vegetation establishment enhances local infiltration capacity, introducing infiltration heterogeneity, thus affecting the topography-controlled flowpaths as water infiltrates at vegetation patches. Critical-zone observatories and monitored early-development systems allow to document signatures of the evolution of catchments and to correlate certain behaviours to processes. However, readily and easily achievable runoff signatures often cannot provide a clear nor full description of process interactions, as the individual roles of processes are stacked together, and strongly shaped by the temporal distribution of rainfall, making it very difficult to disentangle the effects of each process, and making modelling a necessary approach to understand these interactions and their manifestations. All such processes occur at small spatial scales, and are difficult to observe or assess when experimentally studying catchment hydrology. Moreover, given that the complexity of processes contributing to morphological changes and the corresponding alteration of runoff signatures, single catchment experiments and even comprehensive monitoring programmes of whole catchments will neither allow to decipher all processes interactions nor will it allow to apply a statistically derived experimental. In this work, we study the effects that spatial distributions of surface topography and infiltration properties have on surface runoff and surface connectivity in response to single rainfall events, in the context of the Huehnerwasser catchment. We simulate rainfall/runoff processes by means of a physically-based, spatially explicit surface flow model, and assess the results in terms of hydrological signatures (hydrograph, hydrological balance), spatial distribution of the hydrodynamics of runoff, and surface flow connectivity. To do this, we use several DEMs of the H{\"u}hnerwasser catchment recorded during the erosion-based development of the surface (2006-2010), different hypothetical infiltration properties distributions, and a set of different singular rainfall events. The study allows to observe the individual effects that topographic properties and infiltration distributions have on the hydrograph signatures and connect cause-and-effect through an intermediate, conceptual property of the system: surface runoff connectivity, arguably an indicator of hydrological organisation of the runoff response. Moreover, by systematic analysis, the interactions between topography and infiltration can also be assessed in the hydrograph and explained through connectivity. The results show a range of possible magnitudes of influence of topography and infiltration on the runoff response, while highlighting that the onset of runoff and the rising limb of the hydrograph are mostly affected by these features and their interactions, and strongly related to surface runoff connectivity.}, language = {de} } @misc{HinzHafarFischer, author = {Hinz, Christoph and Hafar, Brian and Fischer, Thomas}, title = {Heavy metal mobilisation of salt affected soils and sediments: Assessing the role of chloride complex formation.}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, abstract = {Terrestrial and aquatic ecosystems are increasingly exposed to high level of salt (NaCl) concentrations. Impacts of increased salt concentration on mobilisation of heavy metals have been shown for road side soils receiving de-icing salt, for sediments and soils exposed to salt water intrusions, and soils and aquifers receiving runoff from salt mines. In fact, this study was motivated by the impact of salt dumps on soil and groundwater observed for potash mines in the central part of Germany. The objectives of this contribution is to asses the impact of NaCl concentration on heavy metal mobilization using speciation modelling. In particular, we focus on the effect of chloride complex formation in solution and how strongly this complex formation is "extracting" heavy metal cation from soil and sediments substrates. As experimental data for speciation at very high ionic strength is not readily available and not easily measurable, we focus on PHREEQC modelling to assess NaCl concentration ranges up to 3 M, needing to employ Pitzer equation as the activity model. In order to determine the competition of surface reaction and complex formation in aqueous solution, we used three reaction models: i) surface complexation with a high and low affinity site for iron hydroxide, ii) a heterogeneous binding site model for humic acids and iii) ion exchange as described with Rothmund-Kornfeld equation We did a series of simulations for Zn, Cd and Pb. Species distribution for the aqueous phase and the solid surfaces where determined by increasing NaCl solutions for a given total heavy metal concentration. In nearly all simulations conducted, the difference between simulations allowing chloride complexes to form and simulations where complexation is disabled, showed the emergence of a characteristic concentration range of NaCl for which the effect of chloride complexation reaches a maximum. In general, the range of highest sensitivity concerning mobilization occurs within the range of 1-3M NaCl for all simulations. At the lower end of this range shows the highest sensitivity to NaCl changes and is determined by several factors including the affinity to bonding sites and the speciation of an element along the salinity gradient. The peak of this curve is controlled by the point along the salinity gradient where the majority of heavy metal has been mobilized from the surface phase. One important outcome of this study is, that increasing NaCl background concentration behaves in a nonlinear way that is determined by the heterogeneity of the surface binding sites and that there is no simple way of assessing the mobilization potential of chloride complexation in soils and sediments.}, language = {en} } @misc{AlmawazrehCaviedesVoulliemeHinz, author = {Almawazreh, Albara and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Solute dissipation regimes and rates controlled by soil evaporation and rainfall variability in heterogeneous soils}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, abstract = {Reactive solute leaching from the top soil has received wide attention as it relates to major environmental challenges like groundwater and river water pollution by leached reactive solutes such as agricultural pesticides or biochemical pollutants. Adequate understanding of how fast, when and how such solutes and possible contaminants are leached from the top soil is necessary to enhance agricultural practice, pollution risk assessment and overall water quality management. Many empirical studies have been carried on the subject, with varied their approaches and complexity, and have been carried out under different site and atmospheric conditions. Some ofsuch studies argue that properties of soils and solutes are dominant for the leaching process, while others emphasizeatmospheric drivers as a main trigger for preferential flow. Long residence times have also been observed, with solutes lingering in the soils long after initially introduced and after experiencing rainfall events. Modelling and analytical studies have been put forward to better explain these behaviours, but often neglecting some of of the sources of complexity (such as preferential flow and soil heterogeneity) or with simplified modelling strategies. In this work, we study reactive solute dissipation processes in a soil column with a contaminated top soil layer in response to rainfall events. To cope with a heterogeneous soil structure, within an intermediate-complexity and physically-based framework, we solve Richards equation together with a mobile-immobile soil model together with a non-equilibrium advection-diffusion reaction model in Hydrus1D. We perform an extensive analysis of the sensitivity of solute dissipation rates from the top soil in response to all permutations of a parameter space comprised of soil properties (immobile fraction, mobile-immobile mass transfer coefficient), solute properties (decay coefficient, adsorption coefficient), rainfall parameters (total precipitation, duration, frequency) and the presence or absence of evaporation. Results are assessed in terms of the resulting solute dissipation curves and are fitted to exponential decay curves for comparison purposes. The results show that different solute dissipation regimes exist in response to the dominant physical process under a particular set of conditions. We identify three dissipation regimes which exhibit characteristic time scales and dissipation curve shapes: an advection dominated regime occurring under particular rainfall conditions, an evaporation dominated regime occurring under low rainfall volume and intensity and a decay-dominated regime exists, in which the bio- or chemical- decay rate of the substance is large and therefore dominant. Our results also provide further evidence and rationale for long residence times (which have been previously noted in the literature) in the top soil under preferential flow conditions, as the complex interactions between different processes may favour at mobilisation or immobilisation of the solute, which can be related to the characteristic shapes of the dissipation curves and in turn the regimes. The results allow a better understanding of the controlling processes and the related parameters interactions that dominate each regime. The thorough sensitivity analysis shows that, within those regimes, certain properties have higher weight and respectively more attention should be given when investigating them in comprehensive leaching risk assessment.}, language = {en} } @misc{BrueckRojasCaviedesVoulliemeetal., author = {Br{\"u}ck, Yasemine and Rojas, Pedro and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Processing of aerial images to detect vegetation cover and evaluate transient vegetation patch characteristics of H{\"u}hnerwasser catchment}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, abstract = {The artificial catchment "H{\"u}hnerwasser" was built in a post-mining landscape, as a field experiment to observe and monitor early-development ecosystems at first catchment scale. As vegetation is a key driver of hydrological catchment behavior, spatial distribution and temporal dynamics of vegetation affects water redistribution from plot to catchment scale. In the context of early ecosystem development, quantifying changes in vegetation structures is an obvious indicator for state transitions. The first years of ecosystem development at the H{\"u}hnerwasser catchment showed rapidly increasing complexity of emerging structures associated with rising vegetation cover and increasing number of plant species. This work will focus on characterizing vegetation cover using aerial images aiming to describe spatial structures and how those evolve in time. The early stages are especially of interest. The structure is therefore characterized by the area of the catchment covered by vegetation, the number of vegetation patches, the mean and maximum patch size and a form factor (area of patch divided by its perimeter). Aerial images with a resolution at cm scale were taken once per year from 2007 to 2018. Binary maps are generated by setting thresholds for red, green and blue channels to differentiate between vegetation cover and bare soil. To evaluate the consistency of the binary images of each channel these images were stacked and compared. The performance of the method was tested by using a set of combinations of thresholds and a comparison with manual mapping of vegetation cover at an image subset was made. The blue channel seems to be very sensitive to detect vegetation and a better differentiation of vegetation and dark/wet soil can be achieved by setting the thresholds of the channels in a specific order. The structures derived by the classification into vegetated and bare soil are more important in the early years of ecosystem development. In those years (2007 to 2011) the most changes took place. As time advances vegetation became less patchy and other characteristics need to be implemented to describe the vegetation cover, taking into account different plant functional types.}, language = {en} } @misc{PohleGaedekeSchuembergetal., author = {Pohle, Ina and G{\"a}deke, Anne and Sch{\"u}mberg, Sabine and Hinz, Christoph and Koch, Hagen}, title = {Management Influences on Stream-Flow Variability in the Past and Under Potential Climate Change in a Central European Mining Region}, series = {Water Resource Management}, volume = {33}, journal = {Water Resource Management}, number = {15}, issn = {1573-1650}, doi = {10.1007/s11269-019-02432-3}, pages = {5191 -- 5206}, abstract = {Robust assessments of stream-flow volume and variability under current and potential future conditions are essential for sustainable water resources planning and management. Nonlinear and overlapping responses to climate, land use, and water resources management (WRM) make it difficult to link observed stream-flow variability to individual drivers and to project potential future changes in stream-flow volume and variability. Here, we investigate WRM influences on stream-flow variability for two rivers with similar natural catchment characteristics, the Schwarze Elster and the Spree. The Schwarze Elster is characterized by less intensive WRM compared to the Spree. Management influences on stream-flow variability in the past were analysed by comparing observed managed stream-flow with simulated natural flow (model SWIM). Simulation results of natural flow and managed stream-flow (model WBalMo) forced by different climate scenarios were investigated to assess management influences on potential future stream-flow. The Schwarze Elster shows little management influences on stream-flow both in the past and under future scenarios. WRM related to lignite mining activities rather than natural processes dominated seasonal and annual stream-flow variability of the Spree in the past, while reservoir management mainly impacted short-term variability. Long-term and short-term stream-flow variability of the Spree are expected to be further reduced in future by reservoir management and water transfers to ensure minimum flow requirements. Strong impacts ofWRM in reducing stream-flow variability in future scenarios underline the role of reservoir management as an effective and flexible adaptation option to uncertain climate change impacts on hydrology.}, language = {en} } @misc{KhoshBinGhomashCaviedesVoulliemeHinz, author = {Khosh Bin Ghomash, Shahin and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Effects of topography and infiltration heterogeneity on surface runoff and connectivity in the H{\"u}hnerwasser catchment.}, series = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, journal = {European Geosciences Union, General Assembly 2019, Vienna, Austria, 7-12 April 2019}, address = {Katlenburg-Lindau}, language = {en} } @misc{McGrathSadlerFlemingetal., author = {McGrath, Gavan S. and Sadler, R. and Fleming, K. and Tregoning, P. and Hinz, Christoph and Veneklaas, Erik J.}, title = {Tropical cyclones and the ecohydrology of Australia's recent continental-scale drought}, issn = {0094-8276}, doi = {10.1029/2011GL050263}, language = {en} } @misc{KaestnerHinzCaviedesVoulliemeetal., author = {K{\"a}stner, Karl and Hinz, Christoph and Caviedes-Voulli{\`e}me, Daniel and Frechen, Tobias Nanu and Vijsel, Roeland C van de}, title = {A metaanalysis of the regularity of environmental spatialpatterns and a theory relating them to stochastic processes}, series = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, journal = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, doi = {10.5194/egusphere-egu23-5817}, language = {en} } @misc{ShlewetCaviedesVoulliemeKaestneretal., author = {Shlewet, Marlin and Caviedes-Voulli{\`e}me, Daniel and K{\"a}stner, Karl and Hinz, Christoph}, title = {Effects of urban structures on spatial and temporal flood distribution}, series = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, journal = {EGU General Assembly 2023, Vienna, Austria, 24-28 Apr 2023}, doi = {10.5194/egusphere-egu23-9498}, language = {en} } @misc{KaestnerCaviedesVoulliemeFrechenetal., author = {K{\"a}stner, Karl and Caviedes-Voullieme, Daniel and Frechen, Tobias Nanu and Hinz, Christoph}, title = {Theory and empirical evidence for the irregularity of self-organized vegetation patterns}, series = {EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022}, doi = {10.5194/egusphere-egu22-11905}, abstract = {In arid environments, vegetation tends to self-organize into patches separated by bare soil. This is necessitated by the lack of water for sustaining a continuous vegetation cover and facilitated by the attraction of water from barren interpatch areas by the vegetation. This process is a positive feedback which introduces spatially heterogeneity into otherwise homogeneous environments, characterised by regular patterns. These patterns are typically considered to be periodic and distinguished on hand of their wavelength. Such patterns have so far been studied with numerical models which generate periodic patterns in homogeneous environments. However, environments are rarely homogeneous, as topography and soil-hydraulic properties vary in space. This raises the questions to which degree heterogeneity of vegetation is self-organized or imposed by the environment, and how environmental heterogeneity interacts with the self-organization process. In contrast to the persisting conceptual model of periodic patterns, natural vegetation exhibit a high degree of irregularity. Several studies have linked this irregularity to heterogeneity in the environment, but a comprehensive theory for analysing the irregularity has not yet been established. Furthermore remains the extend of irregularity unexplored on a global scale. To fill this gap, we, demonstrate empirically the global prevalence of irregularity in vegetation patterns and find that natural vegetation patterns are stochastic, rather than periodic. We then propose a stochastic framework to conceptually describe and measure the regularity, based on the spectral density of the patterns. In addition to the dominant wavelength, measuring the spatial scale, it reveals a novel parameter, measuring the regularity. The parameter is determined by the correlation structure and discriminates gradually between the limit cases of periodicity and white noise. Applied to natural and computer-generated patterns, we find that the former are highly irregular, while the latter are close to periodic. We reproduce the stochasticity of patterns with numerical models by introducing spatial heterogeneity of the model coefficients. We provide a fresh look at the nature of vegetations patterns and present a comprehensive theory for a more holistic understanding of self-organized systems.}, language = {en} } @inproceedings{JozefikFrechenHinzetal., author = {Jozefik, Zoltan and Frechen, Tobias Nanu and Hinz, Christoph and Schmidt, Heiko}, title = {A cellular automata approach for modeling surface water runoff}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{FrechenHinzMcGrath, author = {Frechen, Tobias Nanu and Hinz, Christoph and McGrath, Gavan S.}, title = {Relating biomass and vegetation structure in water limited ecosystems using a celluar automata based model}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{ShlewetKaestnerCaviedesVoulliemeetal., author = {Shlewet, Marlin and K{\"a}stner, Karl and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph}, title = {Einfluss urbaner Strukturen auf die r{\"a}umliche und zeitliche Dynamik pluvialer Fluten}, series = {Abstract-Band, Tag der Hydrologie 2023, Nachhaltiges Wassermanagement - Regionale und Globale Strategien, 22. \& 23.03.2023, Ruhr-Universit{\"a}t Bochum \& Hochschule Bochum}, journal = {Abstract-Band, Tag der Hydrologie 2023, Nachhaltiges Wassermanagement - Regionale und Globale Strategien, 22. \& 23.03.2023, Ruhr-Universit{\"a}t Bochum \& Hochschule Bochum}, language = {de} } @inproceedings{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water balance dynamics of the constructed Chicken Creek catchment as influenced by 12 years of ecological development}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Experimental catchments with well-known boundaries and characteristics may contribute valuable data to hydrological, critical zone and landscape evolution research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha area including a 0.4 ha pond, Brandenburg, Germany) representing an initial ecosystem undergoing a highly dynamic ecological development starting from clearly defined starting conditions. The water balance dynamics of the catchment was calculated using a simple mass balance approach to reveal the impact of ecological development during 12 years. Water storage in the catchment was calculated from a 3D-model of groundwater volumes, soil moisture measurements and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Due to the known boundary conditions and the inner structure of the catchment, we were able to quantify the different storage compartments and their role in hydrologic response. Our results indicate that for small catchments with a highly dynamic ecological development like the Chicken Creek, the knowledge about saturated and unsaturated storage volumes enables a good estimate and closure of the water balance using a rather simple approach, at least in annual resolution. We found a significant relationship between vegetation cover in the catchment and calculated ET. Time series of meteorological, hydrological, soil and vegetation data over 12 years enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology. The dataset from the Chicken Creek catchment indicate at least three phases in ecosystem development, where initial abiotic feedbacks (e.g. erosion) were followed by more and more biotic controls (e.g. biological soil crusts, vegetation succession and growth). Data from Chicken Creek in high spatial and temporal resolution provide a valuable database underlining the high importance of abiotic/biotic feedback effects that change the hydrologic functioning and response of the catchment more than the water balance itself revealed and thus have to be included in catchment models.}, language = {en} } @incollection{SchaafHinzGerwinetal., author = {Schaaf, Wolfgang and Hinz, Christoph and Gerwin, Werner and Zaplata, Markus Klemens and H{\"u}ttl, Reinhard F.}, title = {Ecosystem Development in the Constructed Catchment "Chicken Creek"}, series = {Hydrology of Artificial and Controlled Experiments}, booktitle = {Hydrology of Artificial and Controlled Experiments}, editor = {Liu, Jiu-Fu and Gu, Wei-Zu}, publisher = {Intech Open}, address = {London}, isbn = {978-1-78923-559-3}, pages = {75 -- 93}, abstract = {Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances, or transgression of thresholds. We propose a conceptual framework of feedback processes in early states of ecosystem development affected by spatiotemporal environmental drivers. To test this concept, we used 10-year time series of hydrological, biological, geomorphological, and soil data from the constructed catchment Chicken Creek." The 6ha site was left to unrestricted development since 2005 and was intensively monitored. The data showed a very rapid development of the site with an increasing complexity and heterogeneity. In the first years, stochastic signals like the initial substrate conditions and external drivers like extreme weather events were the most important factors resulting in abiotic/abiotic feedback mechanisms shaping the morphology of the site and creating site diversity. Initial abiotic feedback mechanisms between water and substrate were soon followed by abiotic/biotic feedbacks between biological soil crusts, invading vegetation, geomorphology, and hydrology resulting in state transitions of catchment functioning.}, language = {en} } @inproceedings{GerwinSchaafHinzetal., author = {Gerwin, Werner and Schaaf, Wolfgang and Hinz, Christoph and H{\"u}ttl, Reinhard F.}, title = {Monitoring of Ecosystem Development at the Constructed Catchment Chicken Creek}, series = {TERENO International Conference 2014, From Observation to Prediction in Terrestrial Systems, 29 September to 2 October 2014, Book of Abstracts}, booktitle = {TERENO International Conference 2014, From Observation to Prediction in Terrestrial Systems, 29 September to 2 October 2014, Book of Abstracts}, pages = {P2-12}, abstract = {The constructed catchment Chicken Creek was established in 2005 as an experimental landscape laboratory for ecosystem research. The 6 ha area with clearly defined horizontal as well as vertical boundary conditions was left for an unrestricted primary succession. The developing ecosystem offers the opportunity to study most processes occurring at the interface of bio-, pedo-, geo- and hydrosphere. Particularly interactions and feedbacks between different evolving compartments as well as the establishment of ecosystem functions and services can be investigated during the ongoing ecosystem development. The catchment is extensively instrumented since 2005 in order to detect transition stages of the ecosystem. Comprehensive data recorded with a high spatial and temporal resolution include hydrological, geomorphological, pedological, limnological as well as biological parameters. This site offers the unique situation of an early stage ecosystem with highly dynamic system properties. The first years of development were characterized by a fast formation of geomorphological structures due to massive erosion processes at the initially non-vegetated surface. Hydrological processes led to the establishment of a local groundwater body within 5 years. In the following years the influence of biological structures like vegetation patterns gained an increasing importance. Feedbacks between developing vegetation and e.g. hydrological features became more and more dominant. As a result, different phases of ecosystem development could be distinguished until now. This observatory offers manifold possibilities to identify and disentangle complex interactions between ecosystem compartments in situ under natural conditions. The originally low complexity of the system is growing with time facilitating the identification of influences of newly developing structures on ecosystem functions. Thus, it is possible to study effects of small-scale processes on the whole system at the landscape scale. In addition, the highly dynamic initial system properties allow the observation of multifaceted changes of ecosystem properties and functions within short periods of time.}, language = {en} } @inproceedings{ElmerSchaafGerwinetal., author = {Elmer, Michael and Schaaf, Wolfgang and Gerwin, Werner and Hinz, Christoph}, title = {The constructed catchment 'Chicken Creek' - a landscape observatory to analyze processes and feedback mechanisms during initial ecosystem development}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {We investigated the initial development of the landscape observatory 'Chicken Creek', Germany, an artificial catchment with well known boundary conditions and inner structures (Gerwin et al., 2011). Over a period of nine years, we observed considerable changes within the site (Elmer et al., 2013). Both internal and external factors could be identified as driving forces for the formation of structures and patterns in the catchment. Over time, secondary structures and patterns evolved and became more and more important. Invading biota and vegetation succession initialized feedback mechanisms resulting in pattern and habitat formation as well as in increased differentiation, heterogeneity and complexity that are typical characteristics of ecosystems (Schaaf et al., 2013). The processes and feedback mechanisms in the initial development of a new landscape may deviate in rates, intensity, and dominance from those known from mature ecosystems. It is therefore crucial to understand these early phases of ecosystem development and to disentangle the increasingly complex interactions between the evolving terrestrial and aquatic, biotic, and abiotic compartments of the system.}, language = {en} } @inproceedings{HinzSchaafGerwin, author = {Hinz, Christoph and Schaaf, Wolfgang and Gerwin, Werner}, title = {Competing feedbacks drive state transitions during initial catchment evolution: Examples from post-mining landscape and ecosystems evolution}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Within the context of severely disturbed landscapes with little or no ecological memory, such as post-mining landscapes, we propose a simple framework that explains the catchment evolution as a result of competing feedbacks influenced by the initial conditions and the atmospheric drivers such as rainfall intermittency and intensity. The first stage of the evolution is dominated by abiotic feedbacks triggered by rainfall and subsequent fluid flow causing particle mobilisation on the surface and in the subsurface leading to flow concentration or in some instances to densification of surface and subsurface substrates. Subsequently, abiotic-biotic feedbacks start to compete in the sense that biological activity generally stabilizes substrate by preventing particle mobilisation and hence contribute to converting the substrate to a habitat. We suggest that these competing feedbacks may generate alternative stable states in particular under semi-arid and arid climatic conditions, while in temperate often energy limited environments biological process "outcompete" abiotic processes leading to a stable state, in particular from the water balance point of view for comparable geomorphic situations.}, language = {en} } @inproceedings{GerwinSchaafElmeretal., author = {Gerwin, Werner and Schaaf, Wolfgang and Elmer, Michael and Hinz, Christoph}, title = {The constructed catchment Chicken Creek as Critical Zone Observatory under transition}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The constructed catchment Chicken Creek was established in 2005 as an experimental landscape laboratory for ecosystem research. The 6 ha area with clearly defined horizontal as well as vertical boundary conditions was left for an unrestricted primary succession. All Critical Zone elements are represented at this site, which allows the study of most processes occurring at the interface of bio-, pedo-, geo- and hydrosphere. It provides outstanding opportunities for investigating interactions and feedbacks between different evolving compartments during ecosystem development. The catchment is extensively instrumented since 2005 in order to detect transition stages of the ecosystem. Data recorded with a high spatial and temporal resolution include ydrological, geomorphological, pedological, limnological as well as biological parameters.}, language = {en} } @misc{RaabHinzGerwinetal., author = {Raab, Thomas and Hinz, Christoph and Gerwin, Werner and Lehmkuhl, Frank}, title = {Editorial for the Special Issue "Anthropogenic Geomorphology - Geomorphology in the Anthropocene"}, series = {Geomorphology}, volume = {422}, journal = {Geomorphology}, issn = {0169-555X}, doi = {10.1016/j.geomorph.2022.108528}, language = {en} } @inproceedings{ZaplataMaurerBoldtBurischetal., author = {Zaplata, Markus Klemens and Maurer, Thomas and Boldt-Burisch, Katja and Schaaf, Wolfgang and Hinz, Christoph}, title = {An interactive survey panel regarding the effects of mice (Microtus spec.) on a young ecosystem}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{SchaafHinzGerwinetal., author = {Schaaf, Wolfgang and Hinz, Christoph and Gerwin, Werner and Zaplata, Markus Klemens and H{\"u}ttl, Reinhard F.}, title = {The role of feedback mechanisms in the initial development of the constructed catchment Chicken Creek}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water Balance Dynamics during Ten Years of Ecological Development at Chicken Creek Catchment}, series = {Vadose Zone Journal}, volume = {16}, journal = {Vadose Zone Journal}, number = {11}, issn = {1539-1663}, doi = {10.2136/vzj2017.04.0074}, pages = {14}, abstract = {Difficulties in quantitatively closing the water balance of catchments arise when upscaling point measurements and from insufficient knowledge of the physical boundaries, inner structure, and storage volumes of natural catchments. In addition, there is a strong need for generalizing the relationship between catchment characteristics and hydrological response. Therefore, experimental catchments with well-known boundaries and conditions could contribute valuable data to hydrological and critical zone research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha including a pond, Brandenburg, Germany) representing an initial ecosystem undergoing highly dynamic ecological development starting from clearly defined starting conditions. Directly after completion of the construction, extensive monitoring equipment was installed to track the ecosystem development and to capture the spatiotemporal variability of meteorological, hydrological, ecological, and soil conditions and vegetation succession. In this study, we focused on the water balance dynamics of the Chicken Creek catchment for the period 2005 to 2015 as influenced by ecological development. Water storage in the catchment was calculated from a three-dimensional model of groundwater volumes, soil moisture measurements, and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Time series of meteorological, hydrological, and ecological data for 10 yr enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology.}, language = {en} } @misc{HuettlGerwinSchaafetal., author = {H{\"u}ttl, Reinhard F. and Gerwin, Werner and Schaaf, Wolfgang and Zaplata, Markus Klemens and Hinz, Christoph}, title = {A Critical Zone Observatory for detecting ecosystem transition: the constructed catchment Chicken Creek (Germany)}, series = {Procedia Earth and Planetary Science}, volume = {10}, journal = {Procedia Earth and Planetary Science}, doi = {10.1016/j.proeps.2014.08.009}, pages = {46 -- 51}, abstract = {The constructed catchment Chicken Creek was established in 2005 as an experimental landscape laboratory for ecosystem research. The 6 ha area with clearly defined horizontal as well as vertical boundary conditions was left for natural primary succession. All Critical Zone elements are represented at this site, which allows the study of most processes occurring at the interface of bio-, pedo-, geo- and hydrosphere. It provides outstanding opportunities for investigating interactions and feedbacks between different co-evolving compartments. The catchment has been extensively instrumented since 2005. Data are recorded with a high spatial and temporal resolution and include hydrological, geomorphological, pedological, limnological as well as biological parameters in order to detect transition states of the ecosystem. In contrast to other Critical Zone Observatories, this site offers the unique situation of an early stage ecosystem with highly dynamic properties. The first years of development were characterized by a fast formation of geomorphological structures due to massive erosion of the initially non-vegetated surface. Hydrological processes led to the establishment of a local groundwater body within 5 years. In the following years the influence of biological structures like vegetation patterns gained increasing importance. Feedbacks between developing vegetation and e.g. hydrological features became more and more apparent. As a result, different phases of ecosystem development have been distinguished.}, language = {en} } @misc{GerwinBadorreckSchaafetal., author = {Gerwin, Werner and Badorreck, Annika and Schaaf, Wolfgang and Hinz, Christoph and H{\"u}ttl, Reinhard F.}, title = {Das H{\"u}hnerwasser-Einzugsgebiet in SO-Brandenburg im {\"U}bergang von einem abiotischen zu einem biotisch kontrollierten Wasserhaushalt}, series = {Hydrologie und Wasserbewirtschaftung}, volume = {62}, journal = {Hydrologie und Wasserbewirtschaftung}, number = {3}, issn = {0012-0235}, doi = {10.5675/HyWa_2018,3_1}, pages = {134 -- 144}, abstract = {Das H{\"u}hnerwasser-Einzugsgebiet ist ein 6 ha großes, k{\"u}nstlich geschaffenes Wassereinzugsgebiet im Tagebau Welzow-S{\"u}d in S{\"u}dost-Brandenburg. Das Zweischichtsystem mit einer Ton- und einer dar{\"u}ber liegenden Sandschicht wurde im Jahr 2005 fertiggestellt und ohne weitere Rekultivierungsmaßnahmen f{\"u}r Forschungszwecke bereitgestellt. Es l{\"a}sst exemplarisch die Untersuchung der initialen Landschaftsgenese zu. Insbesondere die Entwicklung von einem zun{\"a}chst noch abiotisch kontrollierten hin zu einem biotisch gesteuerten System l{\"a}sst sich hier beobachten. In diesem Beitrag werden beispielhaft einige in diesem Kontext aufgetretene Interaktionen zwischen abiotischen und biotischen Strukturelementen vorgestellt. Dies sind zum einen Erosions- und Sedimentationsprozesse und ihre Wechselwirkungen mit der Vegetation. Zum anderen wird der Einfluss der Vegetation auf die Grundwasserentwicklung dargestellt.}, language = {de} } @misc{HuettlGerwinKoegelKnabneretal., author = {H{\"u}ttl, Reinhard F. and Gerwin, Werner and K{\"o}gel-Knabner, Ingrid and Schulin, Rainer and Hinz, Christoph and Subke, Jens-Arne}, title = {Ecosystems in transition: interactions and feedbacks with an amphasis on the initial development}, series = {Biogeosciences}, volume = {11}, journal = {Biogeosciences}, doi = {doi:10.5194/bg-11-195-2014}, pages = {195 -- 200}, abstract = {In this Special Issue of Biogeosciences on "Ecosystems in transition: Interactions and feedbacks with an emphasis on the initial development", we bring together research on ecosystems undergoing state transitions, including artificially created and naturally formed sites, most of them in an initial stage of development. State transitions of an ecosystem may occur either when a formerly stable system state is disturbed or when a developing system gradually achieves new functions during succession. This special issue presents a collection of observational and experimental studies that focus on processes occurring during state transitions in the development of ecosystems and provide insights into the feedback mechanisms controlling them. These state transitions are studied at multiple scales, ranging from the pore scale to the catchment scale. The contributions collected in this issue can be divided into two main groups: (i) studies dealing with state transition occurring in initial ecosystems without active human interference, and (ii) studies dealing with active restoration of ecosystems after severe disturbances.}, language = {en} } @inproceedings{PohleHuSchaafetal., author = {Pohle, Ina and Hu, Yuzhu and Schaaf, Wolfgang and Gerwin, Werner and Hinz, Christoph}, title = {Hydrogeochemical signatures of catchment evolution - the role of calcium and sulphate release in the constructed H{\"u}hnerwasser ("Chicken Creek") catchment}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The constructed H{\"u}hnerwasser ("Chicken Creek") catchment is an ecohydrological system in an initial state of development. The catchment with an area of 6 ha was built up from quaternary sediments in the post-mining landscape of Lusatia in Eastern Germany and serves as a critical zone observatory for detecting ecosystem transition. The soil substrate is characterized as sands to loamy sands with low carbonate contents but significant amounts of gypsum in the sediments of the catchment. The catchment undergoes a strong transition from an abiotic system in the initial years to a system with growing influence of biota. Concerning the hydrology, a regime shift from surface runoff to groundwater flow dominated processes is significant. It is of interest, whether the catchment transition is also reflected by hydrogeochemical indicators. We assume gypsum dissolution as dominant process at the catchment scale. In order to investigate the hydrogeochemical evolution of the catchment we analysed electric conductivity, calcium and sulphate concentrations and pH-values of biweekly composite samples from 2007-2013 of the atmospheric deposition, of runoff and soil water. The two observation points in the flowing water represent surface runoff and groundwater discharge respectively. Soil water has been analysed at four soil pits in three depths. The monitoring data were provided by the Research Platform Chicken Creek. From the macroscopic data analysis we found an exponential decay of the electric conductivity, calcium and sulphate concentrations in the flowing waters and some of the soil pits. In the flowing water, the decrease slope of the electric conductivity and the calcium and sulphate concentrations is almost identical. The calcium / sulphate molar ratio as an indicator of gypsum dissolution is almost equal to one up to 2010, afterwards more calcium than sulphate is released. The pH-values in the flowing and soil water are generally higher than in the atmospheric deposition, they do show variabilites but no trend behaviour. The time series analyses showed that the interannual variability of the hydrogeochemical properties is less pronounced in the first years of ecosystem development than in the later years. This leads to the conclusion, that in the first years, gypsum dissolution is the major source for calcium and sulphate in the soil and the flowing waters. The increasing interannual variability and changes in the calcium / sulphate ratio in the later years might be interpreted as hydrogeochemical response to the development of vegetation and acidification due to the development of the rhizosphere.}, language = {en} } @inproceedings{HinzGerwinSchaafetal., author = {Hinz, Christoph and Gerwin, Werner and Schaaf, Wolfgang and Elmer, Michael and Fl{\"u}hler, Hannes and Holl{\"a}nder, Hartmut M. and H{\"u}ttl, Reinhard F.}, title = {State transitions in the artificial catchment Huehnerwasser (Chicken Creek): Ecosystems development 8 years after initialization : abstract}, series = {Soil-mediated Drivers of Coupled Biogeochemical and Hydrological Processes across Scales, AGU Chapman Conference Biosphere II, Tucson, Arizona, USA, 21-24 October 2013}, booktitle = {Soil-mediated Drivers of Coupled Biogeochemical and Hydrological Processes across Scales, AGU Chapman Conference Biosphere II, Tucson, Arizona, USA, 21-24 October 2013}, pages = {S. 34}, language = {en} } @misc{GerwinRaabHinzetal., author = {Gerwin, Werner and Raab, Thomas and Hinz, Christoph and Letmathe, Peter and Leuchner, Michael and Roß-Nickoll, Martina and R{\"u}de, Thomas and Trachte, Katja and W{\"a}tzold, Frank and Lehmkuhl, Frank}, title = {Perspectives of lignite post‑mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany?}, series = {Environmental Sciences Europe}, volume = {35}, journal = {Environmental Sciences Europe}, issn = {2190-4715}, doi = {10.1186/s12302-023-00738-z}, abstract = {Background The decision of the German federal government to cease lignite mining until 2038 or—if possible— already earlier until 2030, will cause manifold transition processes in the remaining lignite mining districts of Germany. The two largest districts are located in geographically opposite regions: The Rhineland in the western part and Lusatia in the east of Germany. As particularly these two mining districts will experience severe changes in their socioeconomic as well environmental conditions, the federal government has adopted comprehensive economic support measures. However, the environmental changes will also cause altered ecosystem functions and services to be provided by the future post-mining landscapes. Results In this paper, the two main lignite-producing regions of Germany are compared with regard to their natural and cultural settings. The economic situation and its history are reflected and differences are outlined. Part of the disparities in the cultural development can be explained by very different natural conditions, especially edaphic factors and climatic situation. Because of dissimilar geological settings, different mining technologies were developed and are in use in the two regions with distinct effects on the resulting post-mining landscapes. Conclusion The long-standing and manifold lignite mining activities have radically restructured the landscapes in Lusatia and the Rhineland. With the ongoing decline of the mining industry and its complete cessation, presumably within the next decade, both regions will alter their faces significantly. These changes offer both challenges but also opportunities with respect to the post-mining landscapes and their ecosystem services they are going to provide. The prerequisites for a positive socioeconomic development and for sustainable land-use concepts that also consider ecological aspects are different for both regions. However, or especially because of these differences, the knowledge exchange and experience transfer between both mining regions are pivotal for the success of this extensive transformation process.}, language = {en} } @misc{LehmkuhlGerwinRaabetal., author = {Lehmkuhl, Frank and Gerwin, Werner and Raab, Thomas and Birkhofer, Klaus and Hinz, Christoph and Letmathe, Peter and Leuchner, Michael and Roß-Nickoll, Martina and R{\"u}de, Thomas R. and Trachte, Katja and W{\"a}tzold, Frank}, title = {Perspectives for the lignite post-mining landscapes of the lignite mining landscapes under changing environmental conditions - what can we learn from a comparison between the Rhenish and the Lusatian regions in Germany? : EGU General Assembly 2024, Vienna, Austria \& Online | 14-19 April 2024}, publisher = {Copernicus GmbH}, doi = {10.5194/egusphere-egu24-2791}, abstract = {The German government's decision to phase out lignite mining by 2038 or earlier, as recently 2030 has been agreed for the Rhineland, will trigger a number of transition processes in Germany's remaining lignite mining areas. The two largest lignite mining areas are located in geographically different regions: Rhineland in the west and Lusatia in the east. As the socio-economic and environmental conditions in these two mining areas are set to change dramatically, the German government has adopted extensive economic support measures. However, the environmental changes will also lead to changes in the ecosystem functions and services provided by the future post-mining landscapes. Gerwin et al. (2023) compare the two main lignite producing regions of Germany in terms of their natural and cultural environments. The economic situation and its history are reflected and differences are outlined. Part of the differences in cultural development can be explained by the natural conditions, especially the edaphic factors and the climatic situation. Because of the specific geological settings, tailored mining technologies were developed and used in the two regions, with different effects on the resulting post-mining landscapes. We conclude that the landscapes of Lusatia and the Rhineland have been radically restructured by the long and varied history of lignite mining. Both regions will change significantly as the mining industry continues to decline and is expected to cease altogether within the next decade. These changes in the post-mining landscapes and the ecosystem services will provide both challenges and opportunities. The preconditions for positive socio-economic development and for sustainable land use concepts that also consider ecological aspects are different for the two regions. The exchange of knowledge and experience between the two mining regions is crucial to the success of this major transformation process, despite, or perhaps because of, these differences. Gerwin, W., Raab, T., Birkhofer, K., Hinz, C., Letmathe, P., Leuchner, M., Ro\&\#223;-Nickoll, M., R\&\#252;de, T., Trachte, K., W\&\#228;tzold, F., Lehmkuhl, F. (2023): Perspectives of lignite post-mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany? Environmental Sciences Europe 35:36. https://doi.org/10.1186/s12302-023-00738-z}, language = {en} }