Articles | Volume 21, issue 7 
            
                
                    
            
            
            https://doi.org/10.5194/hess-21-3749-2017
                    © Author(s) 2017. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/hess-21-3749-2017
                    © Author(s) 2017. This work is distributed under 
the Creative Commons Attribution 3.0 License.
                the Creative Commons Attribution 3.0 License.
Form and function in hillslope hydrology: in situ imaging and characterization of flow-relevant structures
                                            Karlsruhe Institute of Technology (KIT), Institute for Water and
River Basin Management, Chair of Hydrology, Karlsruhe, Germany
                                        
                                    Lisa Angermann
                                            Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences,
Section Hydrology, Potsdam, Germany
                                        
                                    
                                            University of Potsdam, Institute of Earth and Environmental Science,
Potsdam, Germany
                                        
                                    Niklas Allroggen
                                            University of Potsdam, Institute of Earth and Environmental Science,
Potsdam, Germany
                                        
                                    Matthias Sprenger
                                            University of Freiburg, Institute of Geo- and Environmental Natural Sciences,
Chair of Hydrology, Freiburg, Germany
                                        
                                    
                                            University of Aberdeen, School of Geosciences, Geography & Environment,
Aberdeen, Scotland, UK
                                        
                                    Theresa Blume
                                            Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences,
Section Hydrology, Potsdam, Germany
                                        
                                    Jens Tronicke
                                            University of Potsdam, Institute of Earth and Environmental Science,
Potsdam, Germany
                                        
                                    Erwin Zehe
                                            Karlsruhe Institute of Technology (KIT), Institute for Water and
River Basin Management, Chair of Hydrology, Karlsruhe, Germany
                                        
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                                    This preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS). 
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                                        Shiqin Wang, Zhixiong Zhang, Shoucai Wei, Wenbo Zheng, Binbin Liu, Matthias Sprenger, Yanjun Shen, and Yizhang Zhang
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2022-391, https://doi.org/10.5194/hess-2022-391, 2023
                                    Revised manuscript not accepted 
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                                        Judith Meyer, Malte Neuper, Luca Mathias, Erwin Zehe, and Laurent Pfister
                                    Hydrol. Earth Syst. Sci., 26, 6163–6183, https://doi.org/10.5194/hess-26-6163-2022, https://doi.org/10.5194/hess-26-6163-2022, 2022
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                                                We identified and analysed the major atmospheric components of rain-intense thunderstorms that can eventually lead to flash floods: high atmospheric moisture, sufficient latent instability, and weak thunderstorm cell motion. Between 1981 and 2020, atmospheric conditions became likelier to support strong thunderstorms. However, the occurrence of extreme rainfall events as well as their rainfall intensity remained mostly unchanged.
                                            
                                            
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                                    The Cryosphere, 16, 4423–4445, https://doi.org/10.5194/tc-16-4423-2022, https://doi.org/10.5194/tc-16-4423-2022, 2022
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                                                We demonstrate how we can reliably estimate the thawed–frozen permafrost interface with its associated uncertainties in subsea permafrost environments using 2D electrical resistivity tomography (ERT) data. In addition, we show how further analyses considering 1D inversion and sensitivity assessments can help quantify and better understand 2D ERT inversion results. Our results illustrate the capabilities of the ERT method to get insights into the development of the subsea permafrost.
                                            
                                            
                                        Anne Hartmann, Markus Weiler, Konrad Greinwald, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 26, 4953–4974, https://doi.org/10.5194/hess-26-4953-2022, https://doi.org/10.5194/hess-26-4953-2022, 2022
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                                                Analyzing the impact of soil age and rainfall intensity on vertical subsurface flow paths in calcareous soils, with a special focus on preferential flow occurrence, shows how water flow paths are linked to the organization of evolving landscapes. The observed increase in preferential flow occurrence with increasing moraine age provides important but rare data for a proper representation of hydrological processes within the feedback cycle of the hydro-pedo-geomorphological system.
                                            
                                            
                                        Ralf Loritz, Maoya Bassiouni, Anke Hildebrandt, Sibylle K. Hassler, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 26, 4757–4771, https://doi.org/10.5194/hess-26-4757-2022, https://doi.org/10.5194/hess-26-4757-2022, 2022
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                                                In this study, we combine a deep-learning approach that predicts sap flow with a hydrological model to improve soil moisture and transpiration estimates at the catchment scale. Our results highlight that hybrid-model approaches, combining machine learning with physically based models, are a promising way to improve our ability to make hydrological predictions.
                                            
                                            
                                        Achim Brauer, Ingo Heinrich, Markus J. Schwab, Birgit Plessen, Brian Brademann, Matthias Köppl, Sylvia Pinkerneil, Daniel Balanzategui, Gerhard Helle, and Theresa Blume
                                    DEUQUA Spec. Pub., 4, 41–58, https://doi.org/10.5194/deuquasp-4-41-2022, https://doi.org/10.5194/deuquasp-4-41-2022, 2022
                            Matthias Sprenger, Pilar Llorens, Francesc Gallart, Paolo Benettin, Scott T. Allen, and Jérôme Latron
                                    Hydrol. Earth Syst. Sci., 26, 4093–4107, https://doi.org/10.5194/hess-26-4093-2022, https://doi.org/10.5194/hess-26-4093-2022, 2022
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                                                Climate change fundamentally alters glaciated high-alpine areas, but it is unclear how this affects riverine sediment transport. As a first step, we aimed to identify the most important processes and source areas in three nested catchments in the Ötztal, Austria, in the past 15 years. We found that areas above 2500 m were crucial and that summer rainstorms were less influential than glacier melt. These findings provide a baseline for studies on future changes in high-alpine sediment dynamics.
                                            
                                            
                                        Samuel Schroers, Olivier Eiff, Axel Kleidon, Ulrike Scherer, Jan Wienhöfer, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 26, 3125–3150, https://doi.org/10.5194/hess-26-3125-2022, https://doi.org/10.5194/hess-26-3125-2022, 2022
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                                                In hydrology the formation of landform patterns is of special interest as changing forcings of the natural systems, such as climate or land use, will change these structures. In our study we developed a thermodynamic framework for surface runoff on hillslopes and highlight the differences of energy conversion patterns on two related spatial and temporal scales. The results indicate that surface runoff on hillslopes approaches a maximum power state.
                                            
                                            
                                        Nils Hinrich Kaplan, Theresa Blume, and Markus Weiler
                                    Hydrol. Earth Syst. Sci., 26, 2671–2696, https://doi.org/10.5194/hess-26-2671-2022, https://doi.org/10.5194/hess-26-2671-2022, 2022
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                                                This study is analyses how characteristics of precipitation events and soil moisture and temperature dynamics during these events can be used to model the associated streamflow responses in intermittent streams. The models are used to identify differences between the dominant controls of streamflow intermittency in three distinct geologies of the Attert catchment, Luxembourg. Overall, soil moisture was found to be the most important control of intermittent streamflow in all geologies.
                                            
                                            
                                        Alexander Sternagel, Ralf Loritz, Brian Berkowitz, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 26, 1615–1629, https://doi.org/10.5194/hess-26-1615-2022, https://doi.org/10.5194/hess-26-1615-2022, 2022
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                                                We present a (physically based) Lagrangian approach to simulate diffusive mixing processes on the pore scale beyond perfectly mixed conditions. Results show the feasibility of the approach for reproducing measured mixing times and concentrations of isotopes over pore sizes and that typical shapes of breakthrough curves (normally associated with non-uniform transport in heterogeneous soils) may also occur as a result of imperfect subscale mixing in a macroscopically homogeneous soil matrix.
                                            
                                            
                                        Heye Reemt Bogena, Martin Schrön, Jannis Jakobi, Patrizia Ney, Steffen Zacharias, Mie Andreasen, Roland Baatz, David Boorman, Mustafa Berk Duygu, Miguel Angel Eguibar-Galán, Benjamin Fersch, Till Franke, Josie Geris, María González Sanchis, Yann Kerr, Tobias Korf, Zalalem Mengistu, Arnaud Mialon, Paolo Nasta, Jerzy Nitychoruk, Vassilios Pisinaras, Daniel Rasche, Rafael Rosolem, Hami Said, Paul Schattan, Marek Zreda, Stefan Achleitner, Eduardo Albentosa-Hernández, Zuhal Akyürek, Theresa Blume, Antonio del Campo, Davide Canone, Katya Dimitrova-Petrova, John G. Evans, Stefano Ferraris, Félix Frances, Davide Gisolo, Andreas Güntner, Frank Herrmann, Joost Iwema, Karsten H. Jensen, Harald Kunstmann, Antonio Lidón, Majken Caroline Looms, Sascha Oswald, Andreas Panagopoulos, Amol Patil, Daniel Power, Corinna Rebmann, Nunzio Romano, Lena Scheiffele, Sonia Seneviratne, Georg Weltin, and Harry Vereecken
                                    Earth Syst. Sci. Data, 14, 1125–1151, https://doi.org/10.5194/essd-14-1125-2022, https://doi.org/10.5194/essd-14-1125-2022, 2022
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                                                Monitoring of increasingly frequent droughts is a prerequisite for climate adaptation strategies. This data paper presents long-term soil moisture measurements recorded by 66 cosmic-ray neutron sensors (CRNS) operated by 24 institutions and distributed across major climate zones in Europe. Data processing followed harmonized protocols and state-of-the-art methods to generate consistent and comparable soil moisture products and to facilitate continental-scale analysis of hydrological extremes.
                                            
                                            
                                        Daniel Rasche, Markus Köhli, Martin Schrön, Theresa Blume, and Andreas Güntner
                                    Hydrol. Earth Syst. Sci., 25, 6547–6566, https://doi.org/10.5194/hess-25-6547-2021, https://doi.org/10.5194/hess-25-6547-2021, 2021
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                                                Cosmic-ray neutron sensing provides areal average soil moisture measurements. We investigated how distinct differences in spatial soil moisture patterns influence the soil moisture estimates and present two approaches to improve the estimate of soil moisture close to the instrument by reducing the influence of soil moisture further afield. Additionally, we show that the heterogeneity of soil moisture can be assessed based on the relationship of different neutron energies.
                                            
                                            
                                        Erwin Zehe, Ralf Loritz, Yaniv Edery, and Brian Berkowitz
                                    Hydrol. Earth Syst. Sci., 25, 5337–5353, https://doi.org/10.5194/hess-25-5337-2021, https://doi.org/10.5194/hess-25-5337-2021, 2021
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                                                This study uses the concepts of entropy and work to quantify and explain the emergence of preferential flow and transport in heterogeneous saturated porous media. We found that the downstream concentration of solutes in preferential pathways implies a downstream declining entropy in the transverse distribution of solute transport pathways. Preferential flow patterns with lower entropies emerged within media of higher heterogeneity – a stronger self-organization despite a higher randomness.
                                            
                                            
                                        Conrad Jackisch, Sibylle K. Hassler, Tobias L. Hohenbrink, Theresa Blume, Hjalmar Laudon, Hilary McMillan, Patricia Saco, and Loes van Schaik
                                    Hydrol. Earth Syst. Sci., 25, 5277–5285, https://doi.org/10.5194/hess-25-5277-2021, https://doi.org/10.5194/hess-25-5277-2021, 2021
                            Anne Hartmann, Markus Weiler, Konrad Greinwald, and Theresa Blume
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-242, https://doi.org/10.5194/hess-2021-242, 2021
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                                                Our field observation-based examination of flow path evolution, soil formation and vegetation succession across ten millennia on calcareous parent material shows how water flow paths and subsurface water storage are linked to the organization of evolving landscapes. We provide important but rare data and observations for a proper handling of hydrologic processes and their role within the feedback cycle of the hydro-pedo-geomorphological system.
                                            
                                            
                                        Jan Bondy, Jan Wienhöfer, Laurent Pfister, and Erwin Zehe
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-174, https://doi.org/10.5194/hess-2021-174, 2021
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                                                The Budyko curve is a widely-used and simple framework to predict the mean water balance of river catchments. While many catchments are in close accordance with the Budyko curve, others show more or less significant deviations. Our study aims at better understanding the role of soil storage characteristics in the mean water balance and offsets from the Budyko curve. Soil storage proved to be a very sensitive property and potentially explains significant deviations from the curve.
                                            
                                            
                                        Alexander Sternagel, Ralf Loritz, Julian Klaus, Brian Berkowitz, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 25, 1483–1508, https://doi.org/10.5194/hess-25-1483-2021, https://doi.org/10.5194/hess-25-1483-2021, 2021
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                                                The key innovation of the study is a method to simulate reactive solute transport in the vadose zone within a Lagrangian framework. We extend the LAST-Model with a method to account for non-linear sorption and first-order degradation processes during unsaturated transport of reactive substances in the matrix and macropores. Model evaluations using bromide and pesticide data from irrigation experiments under different flow conditions on various timescales show the feasibility of the method.
                                            
                                            
                                        Samuel Schroers, Olivier Eiff, Axel Kleidon, Jan Wienhöfer, and Erwin Zehe
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-79, https://doi.org/10.5194/hess-2021-79, 2021
                                    Manuscript not accepted for further review 
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                                                In this study we ask the basic question why surface runoff forms drainage networks and confluences at all and how structural macro form and micro topography is a result of thermodynamic laws. We find that on a macro level hillslopes should tend from negative exponential towards exponential forms and that on a micro level the formation of rills goes hand in hand with drainage network formation of river basins. We hypothesize that we can learn more about erosion processes if we extend this theory.
                                            
                                            
                                        Nicolas Björn Rodriguez, Laurent Pfister, Erwin Zehe, and Julian Klaus
                                    Hydrol. Earth Syst. Sci., 25, 401–428, https://doi.org/10.5194/hess-25-401-2021, https://doi.org/10.5194/hess-25-401-2021, 2021
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                                                Different parts of water have often been used as tracers to determine the age of water in streams. The stable tracers, such as deuterium, are thought to be unable to reveal old water compared to the radioactive tracer called tritium. We used both tracers, measured in precipitation and in a stream in Luxembourg, to show that this is not necessarily true. It is, in fact, advantageous to use the two tracers together, and we recommend systematically using tritium in future studies.
                                            
                                            
                                        Ralf Loritz, Markus Hrachowitz, Malte Neuper, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 25, 147–167, https://doi.org/10.5194/hess-25-147-2021, https://doi.org/10.5194/hess-25-147-2021, 2021
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                                                This study investigates the role and value of distributed rainfall in the runoff generation of a mesoscale catchment. We compare the performance of different hydrological models at different periods and show that a distributed model driven by distributed rainfall yields improved performances only during certain periods. We then step beyond this finding and develop a spatially adaptive model that is capable of dynamically adjusting its spatial model structure in time.
                                            
                                            
                                        Anne Hartmann, Markus Weiler, and Theresa Blume
                                    Earth Syst. Sci. Data, 12, 3189–3204, https://doi.org/10.5194/essd-12-3189-2020, https://doi.org/10.5194/essd-12-3189-2020, 2020
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                                                Our analysis of soil physical and hydraulic properties across two soil chronosequences of 10 millennia in the Swiss Alps provides important observation of the evolution of soil hydraulic behavior. A strong co-evolution of soil physical and hydraulic properties was revealed by the observed change of fast-draining coarse-textured soils to slow-draining soils with a high water-holding capacity in correlation with a distinct change in structural properties and organic matter content.
                                            
                                            
                                        Daniel Beiter, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 24, 5713–5744, https://doi.org/10.5194/hess-24-5713-2020, https://doi.org/10.5194/hess-24-5713-2020, 2020
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                                                We investigated the interactions between streams and their adjacent hillslopes in terms of water flow. It could be revealed that soil structure has a strong influence on how hillslopes connect to the streams, while the groundwater table tells us a lot about when the two connect. This observation could be used to improve models that try to predict whether or not hillslopes are in a state where a rain event will be likely to produce a flood in the stream.
                                            
                                            
                                        Conrad Jackisch, Samuel Knoblauch, Theresa Blume, Erwin Zehe, and Sibylle K. Hassler
                                    Biogeosciences, 17, 5787–5808, https://doi.org/10.5194/bg-17-5787-2020, https://doi.org/10.5194/bg-17-5787-2020, 2020
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                                                We developed software to calculate the root water uptake (RWU) of beech tree roots from soil moisture dynamics. We present our approach and compare RWU to measured sap flow in the tree stem. The study relates to two sites that are similar in topography and weather but with contrasting soils. While sap flow is very similar between the two sites, the RWU is different. This suggests that soil characteristics have substantial influence. Our easy-to-implement RWU estimate may help further studies.
                                            
                                            
                                        Nils Hinrich Kaplan, Theresa Blume, and Markus Weiler
                                    Hydrol. Earth Syst. Sci., 24, 5453–5472, https://doi.org/10.5194/hess-24-5453-2020, https://doi.org/10.5194/hess-24-5453-2020, 2020
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                                                In recent decades the demand for detailed information of spatial and temporal dynamics of the stream network has grown in the fields of eco-hydrology and extreme flow prediction. We use temporal streamflow intermittency data obtained at various sites using innovative sensing technology as well as spatial predictors to predict and map probabilities of streamflow intermittency. This approach has the potential to provide intermittency maps for hydrological modelling and management practices.
                                            
                                            
                                        Benjamin Fersch, Till Francke, Maik Heistermann, Martin Schrön, Veronika Döpper, Jannis Jakobi, Gabriele Baroni, Theresa Blume, Heye Bogena, Christian Budach, Tobias Gränzig, Michael Förster, Andreas Güntner, Harrie-Jan Hendricks Franssen, Mandy Kasner, Markus Köhli, Birgit Kleinschmit, Harald Kunstmann, Amol Patil, Daniel Rasche, Lena Scheiffele, Ulrich Schmidt, Sandra Szulc-Seyfried, Jannis Weimar, Steffen Zacharias, Marek Zreda, Bernd Heber, Ralf Kiese, Vladimir Mares, Hannes Mollenhauer, Ingo Völksch, and Sascha Oswald
                                    Earth Syst. Sci. Data, 12, 2289–2309, https://doi.org/10.5194/essd-12-2289-2020, https://doi.org/10.5194/essd-12-2289-2020, 2020
                            Uwe Ehret, Rik van Pruijssen, Marina Bortoli, Ralf Loritz, Elnaz Azmi, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 24, 4389–4411, https://doi.org/10.5194/hess-24-4389-2020, https://doi.org/10.5194/hess-24-4389-2020, 2020
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                                                In this paper we propose adaptive clustering as a new method for reducing the computational efforts of distributed modelling. It consists of identifying similar-acting model elements during the runtime, clustering them, running the model for just a few representatives per cluster, and mapping their results to the remaining model elements in the cluster. With the example of a hydrological model, we show that this saves considerable computation time, while largely maintaining the output quality.
                                            
                                            
                                        Anne Hartmann, Ekaterina Semenova, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 24, 3271–3288, https://doi.org/10.5194/hess-24-3271-2020, https://doi.org/10.5194/hess-24-3271-2020, 2020
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                                                Our field observation-based examination of flow path evolution, soil formation, and vegetation succession across 10 millennia shows how water flow paths and subsurface water storage are linked to the organization of evolving landscapes.
The increase found in water storage and preferential flow paths with increasing soil age shows the effect of the complex interaction of vegetation and soil development on flow paths, water balance, and runoff formation during landscape evolution.
                                            
                                            
                                        Mirko Mälicke, Sibylle K. Hassler, Theresa Blume, Markus Weiler, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 24, 2633–2653, https://doi.org/10.5194/hess-24-2633-2020, https://doi.org/10.5194/hess-24-2633-2020, 2020
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                                                We could show that distributed soil moisture time series bear a considerable amount of information about dynamic changes in soil moisture. We developed a new method to describe spatial patterns and analyze their persistency. By combining uncertainty propagation with information theory, we were able to calculate the information content of spatial similarity with respect to measurement uncertainty. This does help to understand when and why the soil is drying in an organized manner.
                                            
                                            
                                        Brian Berkowitz and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 24, 1831–1858, https://doi.org/10.5194/hess-24-1831-2020, https://doi.org/10.5194/hess-24-1831-2020, 2020
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                                                We present a 
                                            
                                        blueprintfor a unified modelling framework to quantify chemical transport in both surface water and groundwater systems. There has been extensive debate over recent decades, particularly in the surface water literature, about how to explain and account for long travel times of chemical species that are distinct from water flow (rainfall-runoff) travel times. We suggest a powerful modelling framework known to be robust and effective from the field of groundwater hydrology.
Conrad Jackisch, Kai Germer, Thomas Graeff, Ines Andrä, Katrin Schulz, Marcus Schiedung, Jaqueline Haller-Jans, Jonas Schneider, Julia Jaquemotte, Philipp Helmer, Leander Lotz, Andreas Bauer, Irene Hahn, Martin Šanda, Monika Kumpan, Johann Dorner, Gerrit de Rooij, Stefan Wessel-Bothe, Lorenz Kottmann, Siegfried Schittenhelm, and Wolfgang Durner
                                    Earth Syst. Sci. Data, 12, 683–697, https://doi.org/10.5194/essd-12-683-2020, https://doi.org/10.5194/essd-12-683-2020, 2020
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                                                Soil water content and matric potential are central hydrological state variables. A large variety of automated probes and sensor systems for field monitoring exist. In a field experiment under idealised conditions we compared 15 systems for soil moisture and 14 systems for matric potential. The individual records of one system agree well with the others. Most records are also plausible. However, the absolute values of the different measuring systems span a very large range of possible truths.
                                            
                                            
                                        Dominic Demand, Theresa Blume, and Markus Weiler
                                    Hydrol. Earth Syst. Sci., 23, 4869–4889, https://doi.org/10.5194/hess-23-4869-2019, https://doi.org/10.5194/hess-23-4869-2019, 2019
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                                                This study presents an analysis of 135 soil moisture profiles for identification of the spatial and temporal preferential flow occurrence in a complex landscape. Especially dry conditions and high rainfall intensities were found to increase preferential flow occurrence in soils. This results in a seasonal pattern of preferential flow with a higher occurrence in summer. During this time grasslands showed increased flow velocities, whereas forest sites exhibited a higher amount of bypass flow.
                                            
                                            
                                        Alexander Sternagel, Ralf Loritz, Wolfgang Wilcke, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 23, 4249–4267, https://doi.org/10.5194/hess-23-4249-2019, https://doi.org/10.5194/hess-23-4249-2019, 2019
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                                                We present our hydrological LAST-Model to simulate preferential soil water flow and tracer transport in macroporous soils. It relies on a Lagrangian perspective of the movement of discrete water particles carrying tracer masses through the subsoil and is hence an alternative approach to common models. Sensitivity analyses reveal the physical validity of the model concept and evaluation tests show that LAST can depict well observed tracer mass profiles with fingerprints of preferential flow.
                                            
                                            
                                        Axel Kleidon, Erwin Zehe, and Ralf Loritz
                                        Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2019-52, https://doi.org/10.5194/esd-2019-52, 2019
                                    Manuscript not accepted for further review 
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                                                Many fluxes in Earth systems are not homogeneously distributed across space, but occur highly concentrated in structures, such as turbulent eddies, river networks, vascular networks of plants, or human-made infrastructures.  Yet, the highly-organized nature of these fluxes is typically only described at a rudimentary level, if at all.  We propose that it requires a novel approach to describe these structures that focuses on the work done to build and maintain these structures, and the feedbacks.
                                            
                                            
                                        Ralf Loritz, Axel Kleidon, Conrad Jackisch, Martijn Westhoff, Uwe Ehret, Hoshin Gupta, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 23, 3807–3821, https://doi.org/10.5194/hess-23-3807-2019, https://doi.org/10.5194/hess-23-3807-2019, 2019
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                                                In this study, we develop a topographic index explaining hydrological similarity within a energy-centered framework, with the observation that the majority of potential energy is dissipated when rainfall becomes runoff.
                                            
                                            
                                        Nils Hinrich Kaplan, Ernestine Sohrt, Theresa Blume, and Markus Weiler
                                    Earth Syst. Sci. Data, 11, 1363–1374, https://doi.org/10.5194/essd-11-1363-2019, https://doi.org/10.5194/essd-11-1363-2019, 2019
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                                                Different sensing techniques including time-lapse imagery, electric conductivity and stage measurements were used to generate a combined dataset of the presence and absence of streamflow within a large number of nested sub-catchments in the Attert catchment, Luxembourg. The first sites of observation were established in 2013 and successively extended to a total number of 182 in 2016. The dataset can be used to improve understanding of the temporal and spatial dynamics of the stream network.
                                            
                                            
                                        Matthias Sprenger, Pilar Llorens, Carles Cayuela, Francesc Gallart, and Jérôme Latron
                                    Hydrol. Earth Syst. Sci., 23, 2751–2762, https://doi.org/10.5194/hess-23-2751-2019, https://doi.org/10.5194/hess-23-2751-2019, 2019
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                                                We find that the stable isotopic compositions of mobile and matrix bound soil water are continuously different over 8 months. Long-term data further show that these isotopic differences result from the refilling of small soil pores by isotopically depleted rains during low soil moisture conditions. Thus, subsurface water is not well mixed, but flow velocities and storage in soils are highly variable; this has important implications for ecohydrological studies and soil hydrological modeling.
                                            
                                            
                                        Anne J. Hoek van Dijke, Kaniska Mallick, Adriaan J. Teuling, Martin Schlerf, Miriam Machwitz, Sibylle K. Hassler, Theresa Blume, and Martin Herold
                                    Hydrol. Earth Syst. Sci., 23, 2077–2091, https://doi.org/10.5194/hess-23-2077-2019, https://doi.org/10.5194/hess-23-2077-2019, 2019
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                                                Satellite images are often used to estimate land water fluxes over a larger area. In this study, we investigate the link between a well-known vegetation index derived from satellite data and sap velocity, in a temperate forest in Luxembourg. We show that the link between the vegetation index and transpiration is not constant. Therefore we suggest that the use of vegetation indices to predict transpiration should be limited to ecosystems and scales where the link has been confirmed.
                                            
                                            
                                        Erwin Zehe, Ralf Loritz, Conrad Jackisch, Martijn Westhoff, Axel Kleidon, Theresa Blume, Sibylle K. Hassler, and Hubert H. Savenije
                                    Hydrol. Earth Syst. Sci., 23, 971–987, https://doi.org/10.5194/hess-23-971-2019, https://doi.org/10.5194/hess-23-971-2019, 2019
                            Martijn Westhoff, Axel Kleidon, Stan Schymanski, Benjamin Dewals, Femke Nijsse, Maik Renner, Henk Dijkstra, Hisashi Ozawa, Hubert Savenije, Han Dolman, Antoon Meesters, and Erwin Zehe
                                        Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2019-6, https://doi.org/10.5194/esd-2019-6, 2019
                                    Publication in ESD not foreseen 
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                                                Even models relying on physical laws have parameters that need to be measured or estimated. Thermodynamic optimality principles potentially offer a way to reduce the number of estimated parameters by stating that a system evolves to an optimum state. These principles have been applied successfully within the Earth system, but it is often unclear what to optimize and how. In this review paper we identify commonalities between different successful applications as well as some doubtful applications.
                                            
                                            
                                        Nevil Quinn, Günter Blöschl, András Bárdossy, Attilio Castellarin, Martyn Clark, Christophe Cudennec, Demetris Koutsoyiannis, Upmanu Lall, Lubomir Lichner, Juraj Parajka, Christa D. Peters-Lidard, Graham Sander, Hubert Savenije, Keith Smettem, Harry Vereecken, Alberto Viglione, Patrick Willems, Andy Wood, Ross Woods, Chong-Yu Xu, and Erwin Zehe
                                    Proc. IAHS, 380, 3–8, https://doi.org/10.5194/piahs-380-3-2018, https://doi.org/10.5194/piahs-380-3-2018, 2018
                            Nevil Quinn, Günter Blöschl, András Bárdossy, Attilio Castellarin, Martyn Clark, Christophe Cudennec, Demetris Koutsoyiannis, Upmanu Lall, Lubomir Lichner, Juraj Parajka, Christa D. Peters-Lidard, Graham Sander, Hubert Savenije, Keith Smettem, Harry Vereecken, Alberto Viglione, Patrick Willems, Andy Wood, Ross Woods, Chong-Yu Xu, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 22, 5735–5739, https://doi.org/10.5194/hess-22-5735-2018, https://doi.org/10.5194/hess-22-5735-2018, 2018
                            Mirko Mälicke, Sibylle K. Hassler, Markus Weiler, Theresa Blume, and Erwin Zehe
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2018-396, https://doi.org/10.5194/hess-2018-396, 2018
                                    Manuscript not accepted for further review 
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                                                In this study we use time dependent variograms to identify periods of organized soil moisture during drying. We could identify emerging spatial patterns which imply periods of terrestrial control on soil moisture organization. The coupling of time dependent variograms with density based clustering is a new approach to detect similarity in spatial patterns. The presented method is useful to describe states of organization and improve kriging workflows by extending their prerequisites.
                                            
                                            
                                        Matthias Sprenger, Doerthe Tetzlaff, Jim Buttle, Hjalmar Laudon, and Chris Soulsby
                                    Hydrol. Earth Syst. Sci., 22, 3965–3981, https://doi.org/10.5194/hess-22-3965-2018, https://doi.org/10.5194/hess-22-3965-2018, 2018
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                                                We estimated water ages in the upper critical zone with a soil physical model (SWIS) and found that the age of water stored in the soil, as well as of water leaving the soil via evaporation, transpiration, or recharge, was younger the higher soil water storage (inverse storage effect). Travel times of transpiration and evaporation were different. We conceptualized the subsurface into fast and slow flow domains and the water was usually half as young in the fast as in the slow flow domain.
                                            
                                            
                                        Ralf Loritz, Hoshin Gupta, Conrad Jackisch, Martijn Westhoff, Axel Kleidon, Uwe Ehret, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 22, 3663–3684, https://doi.org/10.5194/hess-22-3663-2018, https://doi.org/10.5194/hess-22-3663-2018, 2018
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                                                In this study we explore the role of spatially distributed information on hydrological modeling. For that, we develop and test an approach which draws upon information theory and thermodynamic reasoning. We show that the proposed set of methods provide a powerful framework for understanding and diagnosing how and when process organization and functional similarity of hydrological systems emerge in time and, hence, when which landscape characteristic is important in a model application.
                                            
                                            
                                        Conrad Jackisch and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 22, 3639–3662, https://doi.org/10.5194/hess-22-3639-2018, https://doi.org/10.5194/hess-22-3639-2018, 2018
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                                                We present a Lagrangian model for non-uniform soil water dynamics. It handles 2-D diffusion (based on a spatial random walk and implicit pore space redistribution) and 1-D advection in representative macropores (as film flow with dynamic interaction with the soil matrix). The interplay between the domains is calculated based on an energy-balance approach which does not require any additional parameterisation. Model tests give insight into the evolution of the non-uniform infiltration patterns.
                                            
                                            
                                        Simon Höllering, Jan Wienhöfer, Jürgen Ihringer, Luis Samaniego, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 22, 203–220, https://doi.org/10.5194/hess-22-203-2018, https://doi.org/10.5194/hess-22-203-2018, 2018
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                                                Hydrological fingerprints are introduced as response targets for sensitivity analysis and combined with a conventional approach using streamflow data for a temporally resolved sensitivity analysis. The joint benefit of both approaches is presented for several headwater catchments. The approach allows discerning a clarified pattern for parameter influences pinpointed to diverse response characteristics and detecting even slight regional differences.
                                            
                                            
                                        Sibylle Kathrin Hassler, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 22, 13–30, https://doi.org/10.5194/hess-22-13-2018, https://doi.org/10.5194/hess-22-13-2018, 2018
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                                                We use sap velocity measurements from 61 trees on 132 days to gain knowledge about the controls of landscape-scale transpiration, distinguishing tree-, stand- and site-specific controls on sap velocity and sap flow patterns and examining their dynamics during the vegetation period. Our results show that these patterns are not exclusively determined by tree characteristics. Thus, including site characteristics such as geology and aspect could be beneficial for modelling or management purposes.
                                            
                                            
                                        Christina Tecklenburg and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 21, 5043–5063, https://doi.org/10.5194/hess-21-5043-2017, https://doi.org/10.5194/hess-21-5043-2017, 2017
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                                                We characterized groundwater–lake exchange patterns and identified their controls based on extensive field measurements. Our measurement design bridges the gap between the detailed local characterisation and low resolution regional investigations. Results indicated strong spatial variability in groundwater inflow rates: large scale inflow patterns correlated with topography and the groundwater flow field and small scale patterns correlated with grainsize distributions of the lake sediment.
                                            
                                            
                                        Matthias Sprenger, Doerthe Tetzlaff, and Chris Soulsby
                                    Hydrol. Earth Syst. Sci., 21, 3839–3858, https://doi.org/10.5194/hess-21-3839-2017, https://doi.org/10.5194/hess-21-3839-2017, 2017
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                                                We sampled the isotopic composition in the top 20 cm at four different sites in the Scottish Highlands at 5 cm intervals over 1 year. The relationship between the soil water isotopic fractionation and evapotranspiration showed a hysteresis pattern due to a lag response to onset and offset of the evaporative losses. The isotope data revealed that vegetation had a significant influence on the soil evaporation with evaporation being double from soils beneath Scots pine compared to heather.
                                            
                                            
                                        Lisa Angermann, Conrad Jackisch, Niklas Allroggen, Matthias Sprenger, Erwin Zehe, Jens Tronicke, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 21, 3727–3748, https://doi.org/10.5194/hess-21-3727-2017, https://doi.org/10.5194/hess-21-3727-2017, 2017
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                                                This study investigates the temporal dynamics and response velocities of lateral preferential flow at the hillslope. The results are compared to catchment response behavior to infer the large-scale implications of the observed processes. A large portion of mobile water flows through preferential flow paths in the structured soils, causing an immediate discharge response. The study presents a methodological approach to cover the spatial and temporal domain of these highly heterogeneous processes.
                                            
                                            
                                        Simon Paul Seibert, Conrad Jackisch, Uwe Ehret, Laurent Pfister, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 21, 2817–2841, https://doi.org/10.5194/hess-21-2817-2017, https://doi.org/10.5194/hess-21-2817-2017, 2017
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                                                Runoff production mechanisms and their corresponding physiographic controls continue to pose major research challenges in catchment hydrology. We propose innovative data-driven diagnostic signatures for overcoming the prevailing status quo in inter-comparison studies. Specifically, we present dimensionless double mass curves which allow us to infer information on runoff generation at the seasonal and annual timescales. The method is based on commonly available data.
                                            
                                            
                                        Ralf Loritz, Sibylle K. Hassler, Conrad Jackisch, Niklas Allroggen, Loes van Schaik, Jan Wienhöfer, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 21, 1225–1249, https://doi.org/10.5194/hess-21-1225-2017, https://doi.org/10.5194/hess-21-1225-2017, 2017
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                                                In this study we examine whether we can step beyond the qualitative character of perceptual models by using them as a blueprint for setting up representative hillslope models. Thereby we test the hypothesis of whether a single hillslope can represent the functioning of an entire lower mesoscale catchment in a spatially aggregated way.
                                            
                                            
                                        Benjamin Müller, Matthias Bernhardt, Conrad Jackisch, and Karsten Schulz
                                    Hydrol. Earth Syst. Sci., 20, 3765–3775, https://doi.org/10.5194/hess-20-3765-2016, https://doi.org/10.5194/hess-20-3765-2016, 2016
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                                                A technology for the spatial derivation of soil texture classes is presented. Information about soil texture is key for predicting the local and regional hydrological cycle. It is needed for the calculation of soil water movement, the share of surface runoff, the evapotranspiration rate and others. Nevertheless, the derivation of soil texture classes is expensive and time-consuming. The presented technique uses soil samples and remotely sensed data for estimating their spatial distribution.
                                            
                                            
                                        Simon Paul Seibert, Uwe Ehret, and Erwin Zehe
                                    Hydrol. Earth Syst. Sci., 20, 3745–3763, https://doi.org/10.5194/hess-20-3745-2016, https://doi.org/10.5194/hess-20-3745-2016, 2016
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                                                While the assessment of "vertical" (magnitude) errors of streamflow simulations is standard practice, "horizontal" (timing) errors are rarely considered. To assess their role, we propose a method to quantify both errors simultaneously which closely resembles visual hydrograph comparison. Our results reveal  differences in time–magnitude error statistics for different flow conditions. The proposed method thus offers novel perspectives for model diagnostics and evaluation.
                                            
                                            
                                        Erwin Zehe and Conrad Jackisch
                                    Hydrol. Earth Syst. Sci., 20, 3511–3526, https://doi.org/10.5194/hess-20-3511-2016, https://doi.org/10.5194/hess-20-3511-2016, 2016
                            Simon Höllering, Jürgen Ihringer, Luis Samaniego, and Erwin Zehe
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2016-249, https://doi.org/10.5194/hess-2016-249, 2016
                                    Preprint withdrawn 
                            Maik Renner, Sibylle K. Hassler, Theresa Blume, Markus Weiler, Anke Hildebrandt, Marcus Guderle, Stanislaus J. Schymanski, and Axel Kleidon
                                    Hydrol. Earth Syst. Sci., 20, 2063–2083, https://doi.org/10.5194/hess-20-2063-2016, https://doi.org/10.5194/hess-20-2063-2016, 2016
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                                                We estimated forest transpiration (European beech) along a steep valley cross section. Atmospheric demand, obtained by the thermodynamic limit of maximum power, is the dominant control of transpiration at all sites.
To our surprise we find that transpiration is rather similar across sites with different aspect (north vs. south) and different stand structure due to systematically varying sap velocities. Such a compensation effect is highly relevant for modeling and upscaling of transpiration.
                                            
                                            
                                        Ingo Heidbüchel, Andreas Güntner, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 20, 1269–1288, https://doi.org/10.5194/hess-20-1269-2016, https://doi.org/10.5194/hess-20-1269-2016, 2016
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                                                Cosmic-ray neutron sensors bridge the gap between point-scale measurements of soil moisture and remote sensing applications. We tested four distinct methods to calibrate the sensor in a temperate forest environment using different soil moisture weighting approaches. While the variable leaf biomass of the deciduous trees had no significant influence on the calibration, it proved necessary to modify the standard calibration method to achieve the best sensor performance.
                                            
                                            
                                        M. Westhoff, E. Zehe, P. Archambeau, and B. Dewals
                                    Hydrol. Earth Syst. Sci., 20, 479–486, https://doi.org/10.5194/hess-20-479-2016, https://doi.org/10.5194/hess-20-479-2016, 2016
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                                                We derived mathematical formulations of relations between relative wetness and gradients driving run-off and evaporation for a one-box model such that, when conductances are optimized with the maximum power principle, the model leads exactly to a point on the Budyko curve.
With dry spells and dynamics in actual evaporation added, the model compared well with catchment observations without calibrating any parameter.
The maximum-power principle may thus be used to derive the Budyko curve.
                                            
                                            
                                        M. Sprenger, T. H. M. Volkmann, T. Blume, and M. Weiler
                                    Hydrol. Earth Syst. Sci., 19, 2617–2635, https://doi.org/10.5194/hess-19-2617-2015, https://doi.org/10.5194/hess-19-2617-2015, 2015
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                                                We present a novel approach that includes information about the pore water stable isotopic composition in inverse model approaches to estimate soil hydraulic parameters. Different approaches are presented and their adequacy regarding the model efficiency, realism and parameter identifiability are discussed. The advantages of the new approach are shown by an application of the inverse estimated parameters to infer the water balance and the transit time for three different study sites.
                                            
                                            
                                        U. Scherer and E. Zehe
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hessd-12-3527-2015, https://doi.org/10.5194/hessd-12-3527-2015, 2015
                                    Revised manuscript not accepted 
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                                                This paper presents the development, parameterization and verification of a process-based soil erosion model for the catchment scale, which balances necessary complexity with greatest possible simplicity. We used the hydrologic model CATFLOW as a platform and further developed it to CATFLOW-SED by integrating approaches to simulate soil erosion. The model was validated on a hierarchy of scales which is characteristic for the governing processes.
                                            
                                            
                                        E. Zehe, U. Ehret, L. Pfister, T. Blume, B. Schröder, M. Westhoff, C. Jackisch, S. J. Schymanski, M. Weiler, K. Schulz, N. Allroggen, J. Tronicke, L. van Schaik, P. Dietrich, U. Scherer, J. Eccard, V. Wulfmeyer, and A. Kleidon
                                    Hydrol. Earth Syst. Sci., 18, 4635–4655, https://doi.org/10.5194/hess-18-4635-2014, https://doi.org/10.5194/hess-18-4635-2014, 2014
                            H. M. Holländer, H. Bormann, T. Blume, W. Buytaert, G. B. Chirico, J.-F. Exbrayat, D. Gustafsson, H. Hölzel, T. Krauße, P. Kraft, S. Stoll, G. Blöschl, and H. Flühler
                                    Hydrol. Earth Syst. Sci., 18, 2065–2085, https://doi.org/10.5194/hess-18-2065-2014, https://doi.org/10.5194/hess-18-2065-2014, 2014
                            U. Ehret, H. V. Gupta, M. Sivapalan, S. V. Weijs, S. J. Schymanski, G. Blöschl, A. N. Gelfan, C. Harman, A. Kleidon, T. A. Bogaard, D. Wang, T. Wagener, U. Scherer, E. Zehe, M. F. P. Bierkens, G. Di Baldassarre, J. Parajka, L. P. H. van Beek, A. van Griensven, M. C. Westhoff, and H. C. Winsemius
                                    Hydrol. Earth Syst. Sci., 18, 649–671, https://doi.org/10.5194/hess-18-649-2014, https://doi.org/10.5194/hess-18-649-2014, 2014
                            J. Wienhöfer and E. Zehe
                                    Hydrol. Earth Syst. Sci., 18, 121–138, https://doi.org/10.5194/hess-18-121-2014, https://doi.org/10.5194/hess-18-121-2014, 2014
                            M. Liu, A. Bárdossy, and E. Zehe
                                    Hydrol. Earth Syst. Sci., 17, 4685–4699, https://doi.org/10.5194/hess-17-4685-2013, https://doi.org/10.5194/hess-17-4685-2013, 2013
                            E. Zehe, U. Ehret, T. Blume, A. Kleidon, U. Scherer, and M. Westhoff
                                    Hydrol. Earth Syst. Sci., 17, 4297–4322, https://doi.org/10.5194/hess-17-4297-2013, https://doi.org/10.5194/hess-17-4297-2013, 2013
                            M. C. Westhoff and E. Zehe
                                    Hydrol. Earth Syst. Sci., 17, 3141–3157, https://doi.org/10.5194/hess-17-3141-2013, https://doi.org/10.5194/hess-17-3141-2013, 2013
                            A. Kleidon, E. Zehe, U. Ehret, and U. Scherer
                                    Hydrol. Earth Syst. Sci., 17, 225–251, https://doi.org/10.5194/hess-17-225-2013, https://doi.org/10.5194/hess-17-225-2013, 2013
                            J. Wienhöfer, K. Germer, F. Lindenmaier, A. Färber, and E. Zehe
                                    Hydrol. Earth Syst. Sci., 13, 1145–1161, https://doi.org/10.5194/hess-13-1145-2009, https://doi.org/10.5194/hess-13-1145-2009, 2009
                            Related subject area
            Subject: Hillslope hydrology | Techniques and Approaches: Instruments and observation techniques
            
                    
                        
                            
                            
                                     
                                Understanding soil loss in Mollisol permanent gully head cuts through hydrological and hydromechanical responses
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                When and where does near-surface runoff occur in a pre-Alpine headwater catchment?
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Mixed-cultivation grasslands enhance runoff generation and reduce soil loss in the restoration of degraded alpine hillsides
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Dynamics of snow melt infiltration into mountain soils: an instrumental approach in the Nant Valley, Swiss Alps
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Assessment of plot-scale sediment transport on young moraines in the Swiss Alps using a fluorescent sand tracer
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Subsurface flow paths in a chronosequence of calcareous soils: impact of soil age and rainfall intensities on preferential flow occurrence
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Evaporation, infiltration and storage of soil water in different vegetation zones in the Qilian Mountains: a stable isotope perspective
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Groundwater fluctuations during a debris flow event in western Norway – triggered by rain and snowmelt
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Satellite rainfall products outperform ground observations for landslide prediction in India
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Characterising hillslope–stream connectivity with a joint event analysis of stream and groundwater levels
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Structural and functional control of surface-patch to hillslope runoff and sediment connectivity in Mediterranean dry reclaimed slope systems
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Distinct stores and the routing of water in the deep critical zone of a snow-dominated volcanic catchment
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                                     
                                Hydrological trade-offs due to different land covers and land uses in the Brazilian Cerrado
                                
                                        
                                            
                                    
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                A sprinkling experiment to quantify celerity–velocity differences at the hillslope scale
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Impacts of a capillary barrier on infiltration and subsurface stormflow in layered slope deposits monitored with 3-D ERT and hydrometric measurements
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Form and function in hillslope hydrology: characterization of subsurface flow based on response observations
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Identification of runoff formation with two dyes in a mid-latitude mountain headwater
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Multiple runoff processes and multiple thresholds control agricultural runoff generation
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Factors influencing stream baseflow transit times in tropical montane watersheds
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Effects of a deep-rooted crop and soil amended with charcoal on spatial and temporal runoff patterns in a degrading tropical highland watershed
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                The water balance components of undisturbed tropical woodlands in the Brazilian cerrado
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Erosion processes in black marl soils at the millimetre scale: preliminary insights from an analogous model
                                
                                        
                                            
                                    
                            
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Monitoring hillslope moisture dynamics with surface ERT for enhancing spatial significance of hydrometric point measurements
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Development and testing of a large, transportable rainfall simulator for plot-scale runoff and parameter estimation
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                True colors – experimental identification of hydrological processes at a hillslope prone to slide
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Assessment of shallow subsurface characterisation with non-invasive geophysical methods at the intermediate hill-slope scale
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Macropore flow of old water revisited: experimental insights from a tile-drained hillslope
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Hillslope characteristics as controls of subsurface flow variability
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Fluorescent particle tracers in surface hydrology: a proof of concept in a semi-natural hillslope
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Soil-water dynamics and unsaturated storage during snowmelt following wildfire
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Use of the 3-D scanner in mapping and monitoring the dynamic degradation of soils: case study of the Cucuteni-Baiceni Gully on the Moldavian Plateau (Romania)
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                A porewater-based stable isotope approach for the investigation of subsurface hydrological processes
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Subsurface lateral flow from hillslope and its contribution to nitrate loading in streams through an agricultural catchment during subtropical rainstorm events
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                The effect of slope steepness and antecedent moisture content on interrill erosion, runoff and sediment size distribution in the highlands of Ethiopia
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Surface and subsurface flow effect on permanent gully formation and upland erosion near Lake Tana in the northern highlands of Ethiopia
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                The benefits of gravimeter observations for modelling water storage changes at the field scale
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Shallow soil moisture – ground thaw interactions and controls – Part 1: Spatiotemporal patterns and correlations over a subarctic landscape
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Shallow soil moisture – ground thaw interactions and controls – Part 2: Influences of water and energy fluxes
                                
                            
                            
                        
                    
                    
                        
                            
                            
                            
                                     
                                Plot and field scale soil moisture dynamics and subsurface wetness control on runoff generation in a headwater in the Ore Mountains
                                
                            
                            
                        
                    
                    
            
        
        Chao Ma, Shoupeng Wang, Dongshuo Zheng, Yan Zhang, Jie Tang, Yanru Wen, and Jie Dong
                                    Hydrol. Earth Syst. Sci., 29, 823–839, https://doi.org/10.5194/hess-29-823-2025, https://doi.org/10.5194/hess-29-823-2025, 2025
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                                                Soil loss results from the hydrological and hydromechanical responses. The soil loss intensity theoretically relates to the soil water storage and the suction stress. This work contributes to exhibiting the close relationship between erosion intensity in the bed and on the slope and the soil water storage and suction stress. The results of this work highlight that antecedent precipitation should be considered in predicting soil loss in the permanent gully rather than solely from rainfall amount.
                                            
                                            
                                        Victor Aloyse Gauthier, Anna Leuteritz, and Ilja van Meerveld
                                        Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-398, https://doi.org/10.5194/hess-2024-398, 2025
                                    Revised manuscript accepted for HESS 
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                                                This study explored the occurrence of flow on and just below the soil surface for 14 small vegetated plots across a pre-Alpine catchment. Overland flow and lateral flow through the topsoil occurred frequently. The spatial variation in the occurrence and amount of flow depended on site characteristics, in particular the Topographic Wetness Index. The amount of flow also depended on the antecedent wetness conditions and total precipitation.
                                            
                                            
                                        Yulei Ma, Yifan Liu, Jesús Rodrigo-Comino, Manuel López-Vicente, and Gao-Lin Wu
                                    Hydrol. Earth Syst. Sci., 28, 3947–3961, https://doi.org/10.5194/hess-28-3947-2024, https://doi.org/10.5194/hess-28-3947-2024, 2024
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                                                Runoff and sediment reduction benefits of hillside mixed grasslands were examined. Cultivated grasslands effectively increased runoff and decreased sediment along ages. Runoff was the dominant factor affecting the soil erosion modulus on alpine hillsides. This implies that protective measures should be prioritized during the initial planting stage of cultivated grasslands on degraded alpine hillsides. 
                                            
                                            
                                        Judith Eeckman, Brian De Grenus, Floreana Miesen, James Thornton, Philip Brunner, and Nadav Peleg
                                        EGUsphere, https://doi.org/10.5194/egusphere-2024-1832, https://doi.org/10.5194/egusphere-2024-1832, 2024
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                                                The fate of liquid water from melting snow in winter and spring is difficult to understand in the mountains. This work uses uncommon methods to accurately track the dynamics of snowmelt and infiltration at different depths in the ground and at different altitudes. The results show that melting snow quickly infiltrates into the upper layers of the soil but is also quickly transferred into the surface layer of the soil along the slopes towards the river.
                                            
                                            
                                        Fabian Maier, Florian Lustenberger, and Ilja van Meerveld
                                    Hydrol. Earth Syst. Sci., 27, 4609–4635, https://doi.org/10.5194/hess-27-4609-2023, https://doi.org/10.5194/hess-27-4609-2023, 2023
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                                                We used a fluorescent sand tracer with afterglow in combination with sprinkling experiments to visualize and determine the movement of sediments on natural hillslopes. We compared the observed transport patterns with the characteristics of the hillslopes. Results show that the fluorescent sand can be used to monitor sediment redistribution on the soil surface and that infiltration on older hillslopes decreased sediment transport due to more developed vegetation cover and root systems.
                                            
                                            
                                        Anne Hartmann, Markus Weiler, Konrad Greinwald, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 26, 4953–4974, https://doi.org/10.5194/hess-26-4953-2022, https://doi.org/10.5194/hess-26-4953-2022, 2022
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                                                Analyzing the impact of soil age and rainfall intensity on vertical subsurface flow paths in calcareous soils, with a special focus on preferential flow occurrence, shows how water flow paths are linked to the organization of evolving landscapes. The observed increase in preferential flow occurrence with increasing moraine age provides important but rare data for a proper representation of hydrological processes within the feedback cycle of the hydro-pedo-geomorphological system.
                                            
                                            
                                        Guofeng Zhu, Leilei Yong, Xi Zhao, Yuwei Liu, Zhuanxia Zhang, Yuanxiao Xu, Zhigang Sun, Liyuan Sang, and Lei Wang
                                    Hydrol. Earth Syst. Sci., 26, 3771–3784, https://doi.org/10.5194/hess-26-3771-2022, https://doi.org/10.5194/hess-26-3771-2022, 2022
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                                                In arid areas, the processes of water storage have not been fully understood in different vegetation zones in mountainous areas. This study monitored the stable isotopes in the precipitation and soil water of the Xiying River Basin. In the four vegetation zones, soil water evaporation intensities were mountain grassland > deciduous forest > coniferous forest > alpine meadow, and soil water storage capacity was alpine meadow > deciduous forest > coniferous forest > mountain grassland.
                                            
                                            
                                        Stein Bondevik and Asgeir Sorteberg
                                    Hydrol. Earth Syst. Sci., 25, 4147–4158, https://doi.org/10.5194/hess-25-4147-2021, https://doi.org/10.5194/hess-25-4147-2021, 2021
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                                                Pore pressure is important for the trigger of debris slides and flows. But how, exactly, does the pore pressure vary just before a slide happens? We drilled and installed a piezometer 1.6 m below the ground in a hillslope susceptible to debris flows in western Norway and measured pore pressure and water temperature through the years 2010–2013. We found the largest anomaly in our groundwater data during the storm named Hilde in November in 2013, when a debris flow happened in this slope.
                                            
                                            
                                        Maria Teresa Brunetti, Massimo Melillo, Stefano Luigi Gariano, Luca Ciabatta, Luca Brocca, Giriraj Amarnath, and Silvia Peruccacci
                                    Hydrol. Earth Syst. Sci., 25, 3267–3279, https://doi.org/10.5194/hess-25-3267-2021, https://doi.org/10.5194/hess-25-3267-2021, 2021
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                                                Satellite and rain gauge data are tested to predict landslides in India, where the annual toll of human lives and loss of property urgently demands the implementation of strategies to prevent geo-hydrological instability. For this purpose, we calculated empirical rainfall thresholds for landslide initiation. The validation of thresholds showed that satellite-based rainfall data perform better than ground-based data, and the best performance is obtained with an hourly temporal resolution.
                                            
                                            
                                        Daniel Beiter, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 24, 5713–5744, https://doi.org/10.5194/hess-24-5713-2020, https://doi.org/10.5194/hess-24-5713-2020, 2020
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                                                We investigated the interactions between streams and their adjacent hillslopes in terms of water flow. It could be revealed that soil structure has a strong influence on how hillslopes connect to the streams, while the groundwater table tells us a lot about when the two connect. This observation could be used to improve models that try to predict whether or not hillslopes are in a state where a rain event will be likely to produce a flood in the stream.
                                            
                                            
                                        Mariano Moreno-de-las-Heras, Luis Merino-Martín, Patricia M. Saco, Tíscar Espigares, Francesc Gallart, and José M. Nicolau
                                    Hydrol. Earth Syst. Sci., 24, 2855–2872, https://doi.org/10.5194/hess-24-2855-2020, https://doi.org/10.5194/hess-24-2855-2020, 2020
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                                                This study shifts from present discussions of the connectivity theory to the practical application of the connectivity concept for the analysis of runoff and sediment dynamics in Mediterranean dry slope systems. Overall, our results provide evidence for the feasibility of using the connectivity concept to understand how the spatial distribution of vegetation and micro-topography (including rills) interact with rainfall dynamics to generate spatially continuous runoff and sediment fluxes.
                                            
                                            
                                        Alissa White, Bryan Moravec, Jennifer McIntosh, Yaniv Olshansky, Ben Paras, R. Andres Sanchez, Ty P. A. Ferré, Thomas Meixner, and Jon Chorover
                                    Hydrol. Earth Syst. Sci., 23, 4661–4683, https://doi.org/10.5194/hess-23-4661-2019, https://doi.org/10.5194/hess-23-4661-2019, 2019
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                                                This paper examines the influence of the subsurface structure on water routing, water residence times, and the hydrologic response of distinct groundwater stores and further investigates their contribution to streamflow. We conclude that deep groundwater from the fractured aquifer system, rather than shallow groundwater, is the dominant source of streamflow, which highlights the need to better characterize the deep subsurface of mountain systems using interdisciplinary studies such as this one.
                                            
                                            
                                        Jamil A. A. Anache, Edson Wendland, Lívia M. P. Rosalem, Cristian Youlton, and Paulo T. S. Oliveira
                                    Hydrol. Earth Syst. Sci., 23, 1263–1279, https://doi.org/10.5194/hess-23-1263-2019, https://doi.org/10.5194/hess-23-1263-2019, 2019
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                                                We assessed the water balance over 5 years in different land uses typical of the Brazilian Cerrado: tropical woodland, bare land, pasture and sugarcane. Land uses may affect hillslope hydrology and cause trade-offs; the woodland consumes the soil water storage along the dry season, while the agricultural LCLU (pasture and sugarcane) reduces the water consumption in either season, and the aquifer recharge rates may be reduced in forested areas due to increased water demand by the vegetation.
                                            
                                            
                                        Willem J. van Verseveld, Holly R. Barnard, Chris B. Graham, Jeffrey J. McDonnell, J. Renée Brooks, and Markus Weiler
                                    Hydrol. Earth Syst. Sci., 21, 5891–5910, https://doi.org/10.5194/hess-21-5891-2017, https://doi.org/10.5194/hess-21-5891-2017, 2017
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                                                How stream water responds immediately to a rainfall or snow event, while the average time it takes water to travel through the hillslope can be years or decades and is poorly understood. We assessed this difference by combining a 24-day sprinkler experiment (a tracer was applied at the start) with a process-based hydrologic model. Immobile soil water, deep groundwater contribution and soil depth variability explained this difference at our hillslope site.
                                            
                                            
                                        Rico Hübner, Thomas Günther, Katja Heller, Ursula Noell, and Arno Kleber
                                    Hydrol. Earth Syst. Sci., 21, 5181–5199, https://doi.org/10.5194/hess-21-5181-2017, https://doi.org/10.5194/hess-21-5181-2017, 2017
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                                                In our study, we used a spatially and temporally high resolved 3-D ERT in addition to matric potential measurements to monitor the infiltration and subsurface water flow on a hillslope with layered slope deposits. We derived some interesting findings about the capillary barrier effect as a main driving factor for the activation of different flow pathways. Thus, the maintenance or breakdown of a capillary barrier has a decisive influence on the precipitation runoff response of of the catchment.
                                            
                                            
                                        Lisa Angermann, Conrad Jackisch, Niklas Allroggen, Matthias Sprenger, Erwin Zehe, Jens Tronicke, Markus Weiler, and Theresa Blume
                                    Hydrol. Earth Syst. Sci., 21, 3727–3748, https://doi.org/10.5194/hess-21-3727-2017, https://doi.org/10.5194/hess-21-3727-2017, 2017
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                                                This study investigates the temporal dynamics and response velocities of lateral preferential flow at the hillslope. The results are compared to catchment response behavior to infer the large-scale implications of the observed processes. A large portion of mobile water flows through preferential flow paths in the structured soils, causing an immediate discharge response. The study presents a methodological approach to cover the spatial and temporal domain of these highly heterogeneous processes.
                                            
                                            
                                        Lukáš Vlček, Kristýna Falátková, and Philipp Schneider
                                    Hydrol. Earth Syst. Sci., 21, 3025–3040, https://doi.org/10.5194/hess-21-3025-2017, https://doi.org/10.5194/hess-21-3025-2017, 2017
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                                                The role of mountain headwater area in hydrological cycle was investigated at two opposite hillslopes covered by mineral and organic soils. Similarities and differences in percolation and preferential flow paths between the hillslopes were identified by sprinkling experiments with Brilliant Blue and Fluorescein. The dye solutions infiltrated into the soil and continued either as lateral subsurface pipe flow (organic soil), or percolated vertically towards the bedrock (mineral soil).
                                            
                                            
                                        Shabnam Saffarpour, Andrew W. Western, Russell Adams, and Jeffrey J. McDonnell
                                    Hydrol. Earth Syst. Sci., 20, 4525–4545, https://doi.org/10.5194/hess-20-4525-2016, https://doi.org/10.5194/hess-20-4525-2016, 2016
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                                                A variety of threshold mechanisms influence the transfer of rainfall to runoff from catchments. Some of these mechanisms depend on the occurrence of intense rainfall and others depend on the catchment being wet. This article first provides a framework for considering which mechanisms are important in different situations and then uses that framework to examine the behaviour of a catchment in Australia that exhibits a mix of both rainfall intensity and catchment wetness dependent thresholds.
                                            
                                            
                                        Lyssette E. Muñoz-Villers, Daniel R. Geissert, Friso Holwerda, and Jeffrey J. McDonnell
                                    Hydrol. Earth Syst. Sci., 20, 1621–1635, https://doi.org/10.5194/hess-20-1621-2016, https://doi.org/10.5194/hess-20-1621-2016, 2016
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                                                This study provides an important first step towards a better understanding of the hydrology of tropical montane regions and the factors influencing baseflow mean transit times (MTT). Our MTT estimates ranged between 1.2 and 2.7 years, suggesting deep and long subsurface pathways contributing to sustain dry season flows. Our findings showed that topography and subsurface permeability are the key factors controlling baseflow MTTs. Longest MTTs were found in the cloud forest headwater catchments.
                                            
                                            
                                        Haimanote K. Bayabil, Tigist Y. Tebebu, Cathelijne R. Stoof, and Tammo S. Steenhuis
                                    Hydrol. Earth Syst. Sci., 20, 875–885, https://doi.org/10.5194/hess-20-875-2016, https://doi.org/10.5194/hess-20-875-2016, 2016
                            P. T. S. Oliveira, E. Wendland, M. A. Nearing, R. L. Scott, R. Rosolem, and H. R. da Rocha
                                    Hydrol. Earth Syst. Sci., 19, 2899–2910, https://doi.org/10.5194/hess-19-2899-2015, https://doi.org/10.5194/hess-19-2899-2015, 2015
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                                                We determined the main components of the water balance for an undisturbed cerrado. 
Evapotranspiration ranged from 1.91 to 2.60mm per day for the dry and wet seasons, respectively. Canopy interception ranged from 4 to 20% and stemflow values were approximately 1% of gross precipitation. 
The average runoff coefficient was less than 1%, while cerrado deforestation has the potential to increase that amount up to 20-fold.
The water storage may be estimated by the difference between P and ET.
                                            
                                            
                                        J. Bechet, J. Duc, M. Jaboyedoff, A. Loye, and N. Mathys
                                    Hydrol. Earth Syst. Sci., 19, 1849–1855, https://doi.org/10.5194/hess-19-1849-2015, https://doi.org/10.5194/hess-19-1849-2015, 2015
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                                                High-resolution three-dimensional point clouds are used to analyse erosion processes at the millimetre scale. The processes analysed here play a role in the closure of cracks. We demonstrated how micro-scale infiltration can influence the degradation of soil surface by inducing downward mass movements that are not reversible. This development will aid in designing future experiments to analyse processes such as swelling, crack closure, micro-landslides, etc.
                                            
                                            
                                        R. Hübner, K. Heller, T. Günther, and A. Kleber
                                    Hydrol. Earth Syst. Sci., 19, 225–240, https://doi.org/10.5194/hess-19-225-2015, https://doi.org/10.5194/hess-19-225-2015, 2015
                            T. G. Wilson, C. Cortis, N. Montaldo, and J. D. Albertson
                                    Hydrol. Earth Syst. Sci., 18, 4169–4183, https://doi.org/10.5194/hess-18-4169-2014, https://doi.org/10.5194/hess-18-4169-2014, 2014
                            P. Schneider, S. Pool, L. Strouhal, and J. Seibert
                                    Hydrol. Earth Syst. Sci., 18, 875–892, https://doi.org/10.5194/hess-18-875-2014, https://doi.org/10.5194/hess-18-875-2014, 2014
                            S. Popp, D. Altdorff, and P. Dietrich
                                    Hydrol. Earth Syst. Sci., 17, 1297–1307, https://doi.org/10.5194/hess-17-1297-2013, https://doi.org/10.5194/hess-17-1297-2013, 2013
                            J. Klaus, E. Zehe, M. Elsner, C. Külls, and J. J. McDonnell
                                    Hydrol. Earth Syst. Sci., 17, 103–118, https://doi.org/10.5194/hess-17-103-2013, https://doi.org/10.5194/hess-17-103-2013, 2013
                            S. Bachmair and M. Weiler
                                    Hydrol. Earth Syst. Sci., 16, 3699–3715, https://doi.org/10.5194/hess-16-3699-2012, https://doi.org/10.5194/hess-16-3699-2012, 2012
                            F. Tauro, S. Grimaldi, A. Petroselli, M. C. Rulli, and M. Porfiri
                                    Hydrol. Earth Syst. Sci., 16, 2973–2983, https://doi.org/10.5194/hess-16-2973-2012, https://doi.org/10.5194/hess-16-2973-2012, 2012
                            B. A. Ebel, E. S. Hinckley, and D. A. Martin
                                    Hydrol. Earth Syst. Sci., 16, 1401–1417, https://doi.org/10.5194/hess-16-1401-2012, https://doi.org/10.5194/hess-16-1401-2012, 2012
                            G. Romanescu, V. Cotiuga, A. Asandulesei, and C. Stoleriu
                                    Hydrol. Earth Syst. Sci., 16, 953–966, https://doi.org/10.5194/hess-16-953-2012, https://doi.org/10.5194/hess-16-953-2012, 2012
                            J. Garvelmann, C. Külls, and M. Weiler
                                    Hydrol. Earth Syst. Sci., 16, 631–640, https://doi.org/10.5194/hess-16-631-2012, https://doi.org/10.5194/hess-16-631-2012, 2012
                            B. Zhang, J. L. Tang, Ch. Gao, and H. Zepp
                                    Hydrol. Earth Syst. Sci., 15, 3153–3170, https://doi.org/10.5194/hess-15-3153-2011, https://doi.org/10.5194/hess-15-3153-2011, 2011
                            M. B. Defersha, S. Quraishi, and A. Melesse
                                    Hydrol. Earth Syst. Sci., 15, 2367–2375, https://doi.org/10.5194/hess-15-2367-2011, https://doi.org/10.5194/hess-15-2367-2011, 2011
                            T. Y. Tebebu, A. Z. Abiy, A. D. Zegeye, H. E. Dahlke, Z. M. Easton, S. A. Tilahun, A. S. Collick, S. Kidnau, S. Moges, F. Dadgari, and T. S. Steenhuis
                                    Hydrol. Earth Syst. Sci., 14, 2207–2217, https://doi.org/10.5194/hess-14-2207-2010, https://doi.org/10.5194/hess-14-2207-2010, 2010
                            B. Creutzfeldt, A. Güntner, S. Vorogushyn, and B. Merz
                                    Hydrol. Earth Syst. Sci., 14, 1715–1730, https://doi.org/10.5194/hess-14-1715-2010, https://doi.org/10.5194/hess-14-1715-2010, 2010
                            X. J. Guan, C. J. Westbrook, and C. Spence
                                    Hydrol. Earth Syst. Sci., 14, 1375–1386, https://doi.org/10.5194/hess-14-1375-2010, https://doi.org/10.5194/hess-14-1375-2010, 2010
                            X. J. Guan, C. Spence, and C. J. Westbrook
                                    Hydrol. Earth Syst. Sci., 14, 1387–1400, https://doi.org/10.5194/hess-14-1387-2010, https://doi.org/10.5194/hess-14-1387-2010, 2010
                            E. Zehe, T. Graeff, M. Morgner, A. Bauer, and A. Bronstert
                                    Hydrol. Earth Syst. Sci., 14, 873–889, https://doi.org/10.5194/hess-14-873-2010, https://doi.org/10.5194/hess-14-873-2010, 2010
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                Short summary
            Rapid subsurface flow in structured soils facilitates fast vertical and lateral redistribution of event water. We present its in situ exploration through local measurements and irrigation experiments. Special emphasis is given to a coherent combination of hydrological and geophysical methods. The study highlights that form and function operate as conjugated pairs. Dynamic imaging through time-lapse GPR was key to observing both and to identifying hydrologically relevant structures.
            Rapid subsurface flow in structured soils facilitates fast vertical and lateral redistribution...