@misc{EllerbrockGerkeBoehm, author = {Ellerbrock, Ruth H. and Gerke, Horst H. and B{\"o}hm, Christian}, title = {In Situ DRIFT Characterization of Organic Matter Composition on Soil Structural Surfaces}, series = {Soil Science Society of America journal : SSSAJ}, volume = {73}, journal = {Soil Science Society of America journal : SSSAJ}, number = {2}, issn = {1435-0661}, doi = {10.2136/sssaj2008.0103}, pages = {531 -- 540}, language = {en} } @inproceedings{LeueEllerbrockGerkeetal., author = {Leue, M. and Ellerbrock, Ruth H. and Gerke, Horst H. and B{\"o}hm, Christian}, title = {In-situ characterization of organic matter composition at aggregate surfaces using DRIFT spectroscopy}, series = {EGU General Assembly 2008, Wien}, booktitle = {EGU General Assembly 2008, Wien}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @incollection{RollandGerkeBiemeltetal., author = {Rolland, Wolfgang and Gerke, Horst H. and Biemelt, Detlef and Schaaf, Wolfgang and K{\"u}gler, R. and K{\"u}gler, Marcus}, title = {Zusammenschau Transportprozesse}, language = {de} } @inproceedings{BartlBiemeltBadorrecketal., author = {Bartl, Steffen and Biemelt, Detlef and Badorreck, Annika and Gerke, Horst H.}, title = {Observations of flow path interactions with surface structures during initial soil development stage using irrigation experiments}, language = {en} } @inproceedings{BartlBiemeltBadorrecketal., author = {Bartl, Steffen and Biemelt, Detlef and Badorreck, Annika and Gerke, Horst H.}, title = {Observations of flow path interactions with surface structures during initial soil development stage using irrigation experiments}, series = {Structures and processes of the initial ecosystem development, 1st International Conference associated with 4th Meeting of Young Researchers in Earth Sciences (MYRES), 20-24 September 2010, Cottbus, Germany, proceedings}, booktitle = {Structures and processes of the initial ecosystem development, 1st International Conference associated with 4th Meeting of Young Researchers in Earth Sciences (MYRES), 20-24 September 2010, Cottbus, Germany, proceedings}, publisher = {BTU}, address = {Cottbus}, pages = {S. 13}, language = {en} } @inproceedings{BartlBiemeltSchappetal., author = {Bartl, Steffen and Biemelt, Detlef and Schapp, Andrea and Henze, Frank and Gerke, Horst H.}, title = {A field rainfall simulator system for the analysis of runoff and infiltration interactions related to soil surface structures}, language = {en} } @inproceedings{BiemeltGerke, author = {Biemelt, Detlef and Gerke, Horst H.}, title = {Hysteretic soil water retention functions from field time series for initial development phases of an artificially-constructed hydrological catchment}, language = {en} } @inproceedings{MaurerSchneiderGerke, author = {Maurer, Thomas and Schneider, Anna and Gerke, Horst H.}, title = {Modelling the initial structure dynamics of soil and sediment exemplified for a constructed hydrological catchment}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Knowledge about spatial heterogeneity is of essential for the analysis of the hydrological catchment behavior. Heterogeneity is directly related to the distribution of the solid phase, and in initial hydrological systems, the solid phase is mainly composed of mineral particles. In artificial catchments, such sediment structures relate to the applied construction technology. It is supposed that the development of catchment ecosystems is strongly influenced by such specific initial spatial distributions of the solid phase. Moreover, during the initial development period, the primary structures in a catchment are altered rapidly by translocation processes, thereby subdividing the initial system in different compartments. Questions are: How does initial sediment distribution affect further structural development? How is catchment hydrology influenced by the initial structural development? What structures have a relevant impact on catchment-scale hydrological behavior?}, language = {en} } @inproceedings{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Raab, Thomas}, title = {Initial phases of landform evolution in a small catchment}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {During initial phases of landform evolution, the surface of sediment bodies is commonly not yet equilibrated with the environmental conditions and is thus liable to rapid changes by accelerated geomorphic activity. Geomorphic processes acting during these early development phases depend on the initial sediment composition and the subsurface and surface structures of the geosystem; at the same time, these processes lead to landscape structures that constitute boundary conditions for further ecosystem development.}, language = {en} } @misc{MaurerGerke, author = {Maurer, Thomas and Gerke, Horst H.}, title = {Processes and modeling of initial landscape development - a review}, series = {Vadose Zone Journal}, volume = {15}, journal = {Vadose Zone Journal}, number = {12}, issn = {1539-1663}, doi = {10.2136/vzj2016.05.0048}, abstract = {The development pathway of a landscape depends to a degree on the initial spatial distributions of mineral and organic components. The interaction between structures and ecohydrological processes during the critical initial development period is scarcely understood and often difficult to observe. While viable modeling approaches exist for most aspects of initial development (e.g., landscape evolution, vegetation succession), a deeper understanding of the prevailing feedback mechanisms requires a comprehensive, integrated modeling approach. We present a review of the current literature regarding the description of initial structures, the state-of-the-art of research on structure-forming processes and their interaction with existing and newly emerging structures, as well as the corresponding modeling efforts. The most relevant aspects are (i) sediment translocation processes and initial evolution of topography, (ii) surface crusting, (iii) vegetation succession, and (iv) the evolution of the soil pore space. Based on existing conceptions for integrated modeling of the coevolution of structures and ecohydrological behavior, we outline an integrative modeling framework that is based on a three-dimensional spatial structural model of initial sediment distributions, which can be used to: (i) analyze the spatiotemporal development dynamics depending on initial structures; and (ii) relate the simulated structural development to available observations of initial ecohydrological development. We discuss possible validation and generalization strategies of modeling results, and propose to define three-dimensional spatial functional catchment units (process domains) characterized by specific structural dynamics and the dominant ecohydrological processes.}, language = {en} } @inproceedings{MaurerSchneiderGerke, author = {Maurer, Thomas and Schneider, Anna and Gerke, Horst H.}, title = {Modelling the initial structure dynamics of soil and sediment exemplified for a constructed hydrological catchment}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The structure of a hydrological catchment is determined by the geometry of the boundaries and the spatial distribution of soil and sediment properties. Models of the 3D subsurface structure and the soil heterogeneity have often been built based on geostatistical approaches and conditional simulations for spatial interpolation between measurements. Here, an alternative model was proposed that generated 3D subsurface structures by imitating basic structures resulting from mass distribution processes. Instead of directly assuming stochastic variations of the subsurface structure, the present approach assumed stochastic variations in parameters of the process-based algorithms of the generator models. The constructed hydrological catchment "H{\"u}hnerwasser" located in the Lower Lusatia region of Brandenburg, Germany, was used as an example for the development of such a 3D structure generator model. Boundary geometries and changes in the surface topography due to erosion and sedimentation processes were quantified on the basis of digital elevation models (DEMs) derived from aerial photographs and terrestrial laser scanning information. Basic sediment properties came i) from a geological model of the parent material at the outcrop site, ii) from actual soil sample measurements on-site, and iii) based on stochastic texture variations. Sediment distributions were generated according to construction processes such as sediment dumping, particle segregation, and soil compaction. The resulting internal structures reflect the formation of spoil cones and surface compaction by machinery. The simulated 3D model scenarios of soil texture and bulk density distributions were incorporated in a gridded 3D volume model using the 3D software tool GoCAD (Paradigm Ltd.). This 3D distributed solid phase structure of the catchment allowed for a more direct comparison with observations using minimal invasive methods. By including structural changes over time (e.g., derived from DEM's), spatially-distributed solid mass balances can be inferred based on the comparison of 3D structure models for subsequent time steps, which is a basic information for studying soil development. The 3D structure model as spatial database of the solid phase allows an integrative analysis, a periodical mass balance, and a mechanistic process-based generation of complex realizations of distributed hydraulic model parameters for the exemplary catchment.}, language = {en} } @inproceedings{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Raab, Thomas}, title = {Evolution of hydro-geomorphic connectivity in an experimental catchment}, series = {American Geophysical Union, Fall Meeting San Franisco, USA, 2014}, booktitle = {American Geophysical Union, Fall Meeting San Franisco, USA, 2014}, abstract = {During initial phases of landform evolution, the surface of sediment bodies is commonly not yet equilibrated with the environmental conditions and is thus liable to rapid changes by accelerated geomorphic activity. Hydro-geomorphic processes acting during these early development phases often lead to the emergence of surface structures that constitute the boundary conditions for further ecosystem development, and of linear erosion features that act as pathways for water, solute and sediment transport, and thus can increase the system's connectivity. Studies on initial landform evolution are often limited to relatively small-scale experiments or rely on modeling exercises. Larger-scale experiments can be carried out in constructed hydrological catchments with well-known and documented initial conditions. The central aim of this work was to describe the hydro-geomorphic surface structure evolution during the initial years of ecosystem development, its dependence on initial and boundary conditions; and on its relations to hydro-geomorphic connectivity. The data are from the 6-ha, constructed hydrological catchment 'H{\"u}hnerwasser'. Hydro-geomorphic development was quantified using a combined analysis of digital elevation models and aerial photographs. Empirical results were compared with those obtained with a numerical landscape evolution model. Phases of rill network growth, contraction and stabilization could be characterized. Results show influences of initial morphology, precipitation characteristics, and developing structure-process-interactions on rill network geometry and connectivity increase in the catchment. The results suggest that phases of hydro-geomorphic surface structure evolution can be related to the spatial organization of surface flow patterns during initial phases of landform development.}, language = {en} } @inproceedings{SchneiderGerke, author = {Schneider, Anna and Gerke, Horst H.}, title = {Initial phases of surface development in a constructed hydrological catchment using the CAESAR landscape evolution model}, series = {European Geosciences Union, General Assembly 2013, Vienna, Austria, 07 - 12 April 2013}, booktitle = {European Geosciences Union, General Assembly 2013, Vienna, Austria, 07 - 12 April 2013}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {High rates of sediment redistribution and a differentiation of geomorphic structures are characteristic for initial phases of surface development. To simulate sediment redistribution in this phase requires a spatially distributed and temporally dynamic soil erosion or landscape evolution model. In this study, we tested the application of the landscape evolution model CAESAR for simulating sediment redistribution during the initial five years of development in a 6 ha artificially created catchment. The objectives were to evaluate effects of input data resolution, initial topographic conditions and climatic influences on surface development by CAESAR simulations. We used a Digital Elevation Model (DEM) of the catchment surface at the initial state of development and hourly precipitation data recorded in the catchment to run the model. Maps of the developing erosion rill network, DEMs for several states of surface development, and discharge data were used for parameter calibration and validation. The influence of DEM resolution, roughness of the input DEM, and precipitation characteristics on model outputs was evaluated. First results show that characteristic patterns of sediment redistribution can be simulated with the landscape evolution model. Resolution of the input DEM was found to affect drainage density of the simulated erosion features. Deviations between the simulated and observed rill network geometry are most probably due to influences of spatially varying sediment hydraulic and mechanical properties on erosion intensity. Results further suggest effects of the initial surface roughness and of precipitation characteristics on the temporal dynamics of rill network development.}, language = {en} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Dynamik der initialen ({\"o}ko-) hydrologischen Entwicklung - Modellierung von Anfangsbedingungen und Wasserfl{\"u}ssen in einem exemplarischen Einzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 20}, language = {de} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Flow processes on the catchment scale - modeling of initial structural states and hydrological behavior in an artificial exemplary catchment}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Landscapes that are heavily disturbed or newly formed by either natural processes or human activity are in a state of disequilibrium. Their initial development is thus characterized by highly dynamic processes under all climatic conditions. The primary distribution and structure of the solid phase (i.e. mineral particles forming the pore space) is one of the decisive factors for the development of hydrological behavior of the eco-hydrological system and therefore (co-) determining for its - more or less - stable final state. The artificially constructed ‚H{\"u}hnerwasser' catchment (a 6 ha area located in the open-cast lignite mine Welzow-S{\"u}d, southern Brandenburg, Germany) is a landscape laboratory where the initial eco-hydrological development is observed since 2005. The specific formation (or construction) processes generated characteristic sediment structures and distributions, resulting in a spatially heterogeneous initial state of the catchment. We developed a structure generator that simulates the characteristic distribution of the solid phase for such constructed landscapes. The program is able to generate quasi-realistic structures and sediment compositions on multiple spatial levels (1 cm up to ∼ 100 m scale). The generated structures can be i) conditioned to actual measurement values (e.g., soil texture and bulk distribution); ii) stochastically generated, and iii) calculated deterministically according to the geology and technical processes at the excavation site. Results are visualized using the GOCAD software package and the free software Paraview. Based on the 3D-spatial sediment distributions, effective hydraulic van-Genuchten parameters are calculated using pedotransfer functions. The hydraulic behavior of different sediment distribution (i.e. versions or variations of the catchment's porous body) is calculated using a numerical model developed by one of us (Caviedes-Voulli{\`e}me). Observation data are available from catchment monitoring are available for i) determining the boundary conditions (e.g., precipitation), and ii) the calibration / validation of the model (catchment discharge, ground water). The analysis of multiple sediment distribution scenarios should allow to approximately determine the influx of starting conditions on initial development of hydrological behavior. We present first flow modeling results for a reference (conditioned) catchment model and variations thereof. We will also give an outlook on further methodical development of our approach.}, language = {en} } @misc{HeinrichBalanzateguiBensetal., author = {Heinrich, Ingo and Balanzategui, Daniel and Bens, Oliver and Blasch, Gerald and Blume, Theresa and B{\"o}ttcher, Falk and Borg, Erik and Brademann, Brian and Brauer, Achim and Conrad, Christopher and Dietze, Elisabeth and Dr{\"a}ger, Nadine and Fiener, Peter and Gerke, Horst H. and G{\"u}ntner, Andreas and Heine, Iris and Helle, Gerhard and Herbrich, Marcus and Harfenmeister, Katharina and Heußner, Karl-Uwe and Hohmann, Christian and Itzerott, Sibylle and Jurasinski, Gerald and Kaiser, Knut and Kappler, Christoph and Koebsch, Franziska and Liebner, Susanne and Lischeid, Gunnar and Merz, Bruno and Missling, Klaus Dieter and Morgner, Markus and Pinkerneil, Sylvia and Plessen, Birgit and Raab, Thomas and Ruhtz, Thomas and Sachs, Torsten and Sommer, Michael and Spengler, Daniel and Stender, Vivien and St{\"u}ve, Peter and Wilken, Florian}, title = {Interdisciplinary Geo-ecological Research across Time Scales in the Northeast German Lowland Observatory (TERENO-NE)}, series = {Vadose Zone Journal}, volume = {17}, journal = {Vadose Zone Journal}, number = {1}, issn = {1539-1663}, doi = {10.2136/vzj2018.06.0116}, pages = {1 -- 25}, language = {en} } @misc{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Seifert, Stefan and Nenov, Rossen and H{\"u}ttl, Reinhard F.}, title = {Evaluation of remotely-sensed DEMs and modification based on plausibility rules and initial sediment budgets of an artificially-created catchment}, series = {Earth Surface Processes and Landforms}, volume = {37}, journal = {Earth Surface Processes and Landforms}, number = {7}, issn = {1096-9837}, pages = {708 -- 725}, language = {en} } @misc{MaurerGerke, author = {Maurer, Thomas and Gerke, Horst H.}, title = {Modelling aeolian sediment transport during initial soil development on an artificial catchment using WEPS and aerial images}, series = {Soil \& Tillage Research}, volume = {117}, journal = {Soil \& Tillage Research}, issn = {0167-1987}, pages = {148 -- 162}, language = {en} } @misc{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Nenov, Rossen}, title = {Initial hydro-geomorphic development and rill network evolution in an artificial catchment}, series = {Earth Surface Processes and Landforms}, volume = {38}, journal = {Earth Surface Processes and Landforms}, number = {13}, issn = {1096-9837}, doi = {10.1002/esp.3384}, pages = {1496 -- 1512}, abstract = {The formation of erosion rills and gullies is a critical step in land surface development, but possibilities to study initial unaffected surface development under natural conditions and with well-defined initial and boundary conditions are rare. The objective of this study was to characterize rill network development from 'point zero' in the artificially-created catchment 'H{\"u}hnerwasser'. To ensure unaffected development, the study was largely restricted to the analysis of remotely-sensed data. We analyzed a series of photogrammetry-based digital elevation models (DEMs) for 10 points in time, over a period of five years and beginning with the initial state. The evolving erosion rill network was quantitatively described based on mapping from aerial photographs. DEMs and rill network maps were combined to specifically analyze the development of morphometry for different parts of the network and to characterize energy dissipation and connectivity. The restriction to remote-sensing data did not allow for analyzing specific processes governing rill network development, nevertheless, two major development phases could be characterized. We observed a phase of growth of the rill network along with variations in drainage patterns during the first two years of development and a subsequent phase of reduction of its area along with comparably stable patterns. Region-specific analysis of morphometry indicates that, besides effects of changing sediment characteristics and vegetation cover development, locally evolving hydro-geomorphic feedback cycles influenced this development. Results show an increasing similarity of overall statistical characteristics (e.g. drainage density) for two parts of the catchment, but a persistent influence of initial conditions on specific rill geometry. The observed development towards higher orderliness and increased connectivity is consistent with experiments and concepts on drainage network evolution across scales; however, we did not observe major influences of rill piracy and cross grading or a reduction of energy dissipation with network development.}, language = {en} } @misc{GerkeMaurerSchneider, author = {Gerke, Horst H. and Maurer, Thomas and Schneider, Anna}, title = {A Three-Dimensional Structure and Process Model for Integrated Hydro-Geo-Pedologic Analysis of a Constructed Hydrological Catchment}, series = {Vadose zone journal}, volume = {12}, journal = {Vadose zone journal}, number = {4}, issn = {1539-1663}, doi = {10.2136/vzj2013.02.0040}, abstract = {A structure model describes the boundary geometries and the three-dimensional solid phase distributions of the catchment. In contrast to an established ecosystem, feedback relations can be assumed for an initial geosystem between the development of spatial structures and the water and element fluxes. The objective was to develop a hydrological catchment model as a three-dimensional spatial database of the solid phase that allows an integrative analysis, a periodical mass balance, and the generation of distributed model parameters for the developing system. Data were from the constructed catchment "Chicken Creek." The initial texture and bulk density distributions were generated by imitating sediment dumping, segregation, and compaction. Boundary geometries and changes in surface topography due to erosion and sedimentation processes were quantified on the basis of digital elevation models (DEMs) derived from aerial photographs. The catchment was visualized with the three-dimensional software GoCad; the "emergence" of the water table and other structures (e.g., soil horizons, root zone) could be spatially assigned and quantified to identify regions with specific processes. A combination of three-dimensional catchment with time-dependent two-dimensional surface models allowed generating the development of spatially distributed erosion-deposition patterns that formed new initial surfaces. The three-dimensional distributed solid phase structure of the catchment allowed for a more direct comparison with observations using minimal invasive methods. The mass balance of the solids could be related with pedologic development and transfer to other geopedologic systems achieved by adapting sediment transport and deposition in the descriptions of the model. This model may help improve the integrative analysis of hydrological catchments.}, language = {en} } @misc{NgoGerkeBadorreck, author = {Ngo, Viet V. and Gerke, Horst H. and Badorreck, Annika}, title = {Estimability Analysis for Optimization of Hysteretic Soil Hydraulic Parameters Using Data of a Field Irrigation Experiment}, series = {Transport in Porous Media}, volume = {103}, journal = {Transport in Porous Media}, number = {3}, doi = {10.1007/s11242-014-0315-6}, pages = {535 -- 562}, abstract = {To improve the quality of parameter optimization, estimability analysis has been proposed as the first step before inverse modeling. When using field data of irrigation experiments for the determination of soil hydraulic parameters, wetting and drying processes may complicate optimization. The objectives of this study were to compare estimability analysis and inverse optimization of the soil hydraulic parameters in the models with and without considering hysteresis of the soil water retention function. Soil water pressure head data of a field irrigation experiment were used. The one-dimensional vertical water movement in variably saturated soil was described with the Richards equation using the HYDRUS-1D code. Estimability of the unimodal van Genuchten-Mualem hydraulic model parameters as well as of the hysteretic parameter model of Parker and Lenhard was classified according to a sensitivity coefficient matrix. The matrix was obtained by sequentially calculating effects of initial parameter variations on changes in the simulated pressure head values.Optimization was carried out by means of the Levenberg-Marquardt method implemented in the HYDRUS-1D code. The parameters α, Ks, θs, and n in the nonhysteretic model were found sensitive and parameter θs strongly correlated with parameter n. When assuming hysteresis, the estimability was decreased with soil depth for Ks and αd , and increased for θs and n. Among the shape parameters, αw was the most estimable. The hysteretic model could approximate the pressure heads in the soil by considering parameters from wetting and drying periods separately as initial estimates. The inverse optimization could be carried out more efficiently with most estimable parameters. Despite the remaining weaknesses of the local optimization algorithm and the inflexibility of the unimodal van Genuchten model, the results suggested that estimability analysis could be considered as a guidance to better define the optimization scenarios and then improved the determination of soil hydraulic parameters.}, language = {en} }