TY - GEN A1 - Blume, Theresa A1 - Zehe, Erwin A1 - Bronstert, Axel T1 - Use of soil moisture dynamics and patterns at different spatio-temporal scales for the investigation of subsurface flow processes N2 - Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes) than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale) and binary indicator maps (for the long-term and hillslope scale). Annual dynamics of soil moisture and decimeterscale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a datascarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to self-reinforcing flow paths. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 125 KW - Repellent sandy soil KW - Poorly gauged catchment KW - Volcanic ash soils KW - Water repellency KW - Preferential flow Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44924 ER - TY - JOUR A1 - Hellmann, Uwe A1 - Rettweiler, Udo A1 - Kramer, Annette A1 - Zehe, Erwin A1 - Jacob, Andreas A1 - Hafner, Johann Evangelist A1 - Tronicke, Jens A1 - Mühle, Ralf-Udo A1 - Klauss, Susanne A1 - Dietrich, Larissa A1 - Richter, Norbert A1 - Schweigl, Kerstin T1 - Portal = Ressource Wasser: Mehr als ein Elixier des Lebens BT - Die Potsdamer Universitätszeitung N2 - Aus dem Inhalt: - Ressource Wasser: Mehr als ein Elixier des Lebens - Dorniges hinter Glas - Die Profstars 2007 - Technik gegen unerwünschte Mithörer entwickelt T3 - Portal: Das Potsdamer Universitätsmagazin - 04-05/2007 Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-440051 SN - 1618-6893 IS - 04-05/2007 ER - TY - GEN A1 - Loritz, Ralf A1 - Hassler, Sibylle K. A1 - Jackisch, Conrad A1 - Allroggen, Niklas A1 - van Schaik, Loes A1 - Wienhöfer, Jan A1 - Zehe, Erwin T1 - Picturing and modeling catchments by representative hillslopes T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - This study explores the suitability of a single hillslope as a parsimonious representation of a catchment in a physically based model. We test this hypothesis by picturing two distinctly different catchments in perceptual models and translating these pictures into parametric setups of 2-D physically based hillslope models. The model parametrizations are based on a comprehensive field data set, expert knowledge and process-based reasoning. Evaluation against streamflow data highlights that both models predicted the annual pattern of streamflow generation as well as the hydrographs acceptably. However, a look beyond performance measures revealed deficiencies in streamflow simulations during the summer season and during individual rainfall-runoff events as well as a mismatch between observed and simulated soil water dynamics. Some of these shortcomings can be related to our perception of the systems and to the chosen hydrological model, while others point to limitations of the representative hillslope concept itself. Nevertheless, our results confirm that representative hillslope models are a suitable tool to assess the importance of different data sources as well as to challenge our perception of the dominant hydrological processes we want to represent therein. Consequently, these models are a promising step forward in the search for the optimal representation of catchments in physically based models. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 635 KW - soil-moisture dynamics KW - hydrologic-response simulation KW - rainfall-runoff response KW - preferential flow KW - subsurface stormflow KW - water-uptake KW - field-scale KW - transport KW - system KW - basin Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419082 IS - 635 SP - 1225 EP - 1249 ER - TY - CHAP A1 - Kühling, Matthias A1 - Märker, Michael A1 - Zehe, Erwin ED - Gzik, Axel ED - Hochschild, Volker ED - Schneider, Ingo ED - Schröder, Boris T1 - Musterdynamik und Fernerkundung in der Döberitzer Heide : [Poster] N2 - Mit der politischen Wende in den Staaten des ehemaligen Ostblockes wurde für viele militärisch genutzte Flächen ein tiefgreifender Nutzungswandel eingeleitet. Truppenübungsplätze als stark gestörte Bestandteile unserer Kulturlandschaft weisen auf großen Flächen naturschutzfachlich wertvolle Habitatmosaike mit speziellen Lebensgemeinschaften auf. Der Nutzungswandel ist mit einer Veränderung der Vegetationsstrukturen (Sukzession) und weiteren landschaftsökologischen Prozessen verbunden. Der ehemalige Truppenübungsplatz Döberitz im Norden der Landeshauptstadt Potsdam kann auf eine lange militärische Nutzungsgeschichte verweisen (erste Manöver des Soldatenkönigs im Jahr 1713). Nach 1992 wurden das NSG Döberitzer Heide (3.415 ha) und das NSG Ferbitzer Bruch (1.155 ha) ausgewiesen. Als Schutzgebiete nach der Vogelschutzrichtlinie sind sie Bestandteile des kohärenten Schutzgebietssystems Natura 2000 der europäischen Gemeinschaft. Trotz des Schutzstatus und der militärischen Altlasten unterliegt das Gebiet als größte zusammenhängende Naturfläche im engeren Verflechtungsraum des Landes Brandenburg einem hohen Nutzungsdruck.
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7277 ER - TY - CHAP A1 - Zehe, Erwin A1 - Bronstert, Axel A1 - Itzerott, Sibylle A1 - Bárdossy, András A1 - Ihringer, Jürgen T1 - Hochwasservorhersage, Großhangbewegungen, Schadstofftransport BT - IMAF-relevante Projektbeispiele und Vorhaben am Institut für Geoökologie N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7128 ER - TY - GEN A1 - Jackisch, Conrad A1 - Angermann, Lisa A1 - Allroggen, Niklas A1 - Sprenger, Matthias A1 - Blume, Theresa A1 - Tronicke, Jens A1 - Zehe, Erwin T1 - Form and function in hillslope hydrology BT - in situ imaging and characterization of flow-relevant structures T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR) methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR "trenches". We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study) and the hydrological processes (companion study Angermann et al., 2017, this issue). T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 665 KW - Ground Penetrating Radar KW - preferential flow KW - solute transport KW - Catchment Hydrology KW - multiple scales KW - soil moisture KW - water content KW - tracer KW - field KW - model Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419188 SN - 1866-8372 IS - 665 ER - TY - GEN A1 - Angermann, Lisa A1 - Jackisch, Conrad A1 - Allroggen, Niklas A1 - Sprenger, Matthias A1 - Zehe, Erwin A1 - Tronicke, Jens A1 - Weiler, Markus A1 - Blume, Theresa T1 - Form and function in hillslope hydrology BT - characterization of subsurface flow based on response observations T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The phrase form and function was established in architecture and biology and refers to the idea that form and functionality are closely correlated, influence each other, and co-evolve. We suggest transferring this idea to hydrological systems to separate and analyze their two main characteristics: their form, which is equivalent to the spatial structure and static properties, and their function, equivalent to internal responses and hydrological behavior. While this approach is not particularly new to hydrological field research, we want to employ this concept to explicitly pursue the question of what information is most advantageous to understand a hydrological system. We applied this concept to subsurface flow within a hillslope, with a methodological focus on function: we conducted observations during a natural storm event and followed this with a hillslope-scale irrigation experiment. The results are used to infer hydrological processes of the monitored system. Based on these findings, the explanatory power and conclusiveness of the data are discussed. The measurements included basic hydrological monitoring methods, like piezometers, soil moisture, and discharge measurements. These were accompanied by isotope sampling and a novel application of 2-D time-lapse GPR (ground-penetrating radar). The main finding regarding the processes in the hillslope was that preferential flow paths were established quickly, despite unsaturated conditions. These flow paths also caused a detectable signal in the catchment response following a natural rainfall event, showing that these processes are relevant also at the catchment scale. Thus, we conclude that response observations (dynamics and patterns, i.e., indicators of function) were well suited to describing processes at the observational scale. Especially the use of 2-D time-lapse GPR measurements, providing detailed subsurface response patterns, as well as the combination of stream-centered and hillslope-centered approaches, allowed us to link processes and put them in a larger context. Transfer to other scales beyond observational scale and generalizations, however, rely on the knowledge of structures (form) and remain speculative. The complementary approach with a methodological focus on form (i.e., structure exploration) is presented and discussed in the companion paper by Jackisch et al. (2017). T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 658 KW - ground-penetrating radar KW - preferential flow KW - water-flow KW - runoff generation KW - vadose zone KW - catchment KW - scale KW - tracer KW - time KW - pore Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419161 SN - 1866-8372 IS - 658 ER - TY - GEN A1 - Wienhöfer, Jan A1 - Germer, Kai A1 - Lindenmaier, Falk A1 - Färber, Arne A1 - Zehe, Erwin T1 - Applied tracers for the observation of subsurface stormflow at the hillslope scale N2 - Rain fall-runoff response in temperate humid headwater catchments is mainly controlled by hydrolo gical processes at the hillslope scale. Applied tracer experiments with fluore scent dye and salt tracers are well known tools in groundwater studies at the large scale and vadose zone studies at the plot scale, where they provide a means to characterise subsurface flow. We extend this approach to the hillslope scale to investigate saturated and unsaturated flow path s concertedly at a forested hill slope in the Austrian Alps. Dye staining experiments at the plot scale revealed that crack s and soil pipe s function as preferential flow path s in the fine-textured soils of the study area, and these preferenti al flow structures were active in fast subsurface transport of tracers at the hillslope scale. Breakthrough curves obtained under steady flow conditions could be fitted well to a one-dimensional convection-dispersion model. Under natural rain fall a positive correlation of tracer concentrations to the transient flows was observed. The results of this study demon strate qualitative and quantitative effects of preferential flow feature s on subsurface stormflow in a temperate humid headwater catchment. It turn s out that , at the hill slope scale, the interaction s of structures and processes are intrinsically complex, which implies that attempts to model such a hillslope satisfactorily require detailed investigation s of effective structures and parameters at the scale of interest. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 146 KW - Saturated hydraulic conductivity KW - preferential flow pathways KW - solute transport KW - runoff generation KW - fluorescent dyes Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45246 ER - TY - GEN A1 - Reusser, Dominik A1 - Blume, Theresa A1 - Schaefli, Bettina A1 - Zehe, Erwin T1 - Analysing the temporal dynamics of model performance for hydrological models N2 - The temporal dynamics of hydrological model performance gives insights into errors that cannot be obtained from global performance measures assigning a single number to the fit of a simulated time series to an observed reference series. These errors can include errors in data, model parameters, or model structure. Dealing with a set of performance measures evaluated at a high temporal resolution implies analyzing and interpreting a high dimensional data set. This paper presents a method for such a hydrological model performance assessment with a high temporal resolution and illustrates its application for two very different rainfall-runoff modeling case studies. The first is the Wilde Weisseritz case study, a headwater catchment in the eastern Ore Mountains, simulated with the conceptual model WaSiM-ETH. The second is the Malalcahuello case study, a headwater catchment in the Chilean Andes, simulated with the physicsbased model Catflow. The proposed time-resolved performance assessment starts with the computation of a large set of classically used performance measures for a moving window. The key of the developed approach is a data-reduction method based on self-organizing maps (SOMs) and cluster analysis to classify the high-dimensional performance matrix. Synthetic peak errors are used to interpret the resulting error classes. The final outcome of the proposed method is a time series of the occurrence of dominant error types. For the two case studies analyzed here, 6 such error types have been identified. They show clear temporal patterns, which can lead to the identification of model structural errors. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 140 KW - Rainfall-runoff response KW - Process identification KW - Improved calibration KW - Soil-moisture KW - Catchment Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-45114 ER -