@misc{SeiffertNenovMaureretal., author = {Seiffert, Thomas and Nenov, Rossen and Maurer, Thomas and Gerwin, Werner and Veste, Maik and Raab, Thomas}, title = {Microdrone-based photogrammetry for water catchment monitoring}, series = {Dimensions of ecology - from global change to molecular ecology, (Gf{\"O}) 39th annual conference, University of Bayreuth, 14th - 18th September 2009}, journal = {Dimensions of ecology - from global change to molecular ecology, (Gf{\"O}) 39th annual conference, University of Bayreuth, 14th - 18th September 2009}, editor = {Holzheu, Stefan and Thies, B.}, publisher = {Bayreuther Zentrum f{\"u}r {\"O}kologie und Umweltforschung (BayCEER) Selbstverlag}, address = {Bayreuth}, pages = {S. 129}, 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{ByizigiroRaabMaurer, author = {Byizigiro, Rutazuyaza Vaillant and Raab, Thomas and Maurer, Thomas}, title = {Small-scale opencast mining: an important research field for anthropogenic geomorphology}, series = {Die Erde}, volume = {146}, journal = {Die Erde}, number = {4}, doi = {10.12854/erde-146-21}, pages = {213 -- 231}, abstract = {Artisanal and small-scale mining (A\&SM) is a growing economic sector in many third-world countries. This review focuses on anthropo-geomorphic factors and processes associated with small-scale opencast mining (SSOM), a form of A\&SM in which near-surface ores are extracted by removing relatively thin covers of soil, bedrock or sediments. Being widespread and commonly conducted without proper planning and beyond the control of local authorities, this form of mining has potentially large impacts on landforms and landscape dynamics, often resulting in drastic consequences for the local environment and agriculture. SSOM should be regarded as a component of anthropogenic geomorphology because it involves the role of humans in creating landforms and modifying the operation of natural geomorphological processes, such as weathering, erosion, transport and deposition. By initiating new and modifying natural geomorphic processes, SSOM causes and/or accelerates geomorphic processes, resulting in various forms of land degradation. While the direct geomorphic impact of SSOM is in general easily discernible and leads to characteristic features, such as excavated pits and overburden spoil heaps, many secondary impacts are attributed to geomorphic processes triggered in the wake of the primary mining-induced landscape alterations. The magnitude of such secondary implications may well extend beyond the actual mining areas, but these effects have not been thoroughly addressed in the research so far. This review summarizes the known studies on the geomorphic impacts of SSOM operations and highlights common geomorphic processes and landforms associated with this type of anthropogenic activity, thus establishing a starting point for further in-depth research.}, 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} } @misc{RaabKruemmelbeinSchneideretal., author = {Raab, Thomas and Kr{\"u}mmelbein, Julia and Schneider, Anna and Gerwin, Werner and Maurer, Thomas and Naeth, M. Anne}, title = {Initial Ecosystem Processes as Key Factors of Landscape Development - A Review}, series = {Physical Geography}, volume = {33}, journal = {Physical Geography}, number = {4}, issn = {1930-0557}, pages = {305 -- 343}, language = {en} } @inproceedings{SchneiderGerkeMaureretal., author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas and Nenov, Rossen and Raab, Thomas}, title = {Hydro-geomorphic differentiation of an artificial catchment during the initial phase of ecosystem development}, series = {AGU Fall Meeting 2011, San Francisco, Calif., 5-9 Dec. 2011}, booktitle = {AGU Fall Meeting 2011, San Francisco, Calif., 5-9 Dec. 2011}, pages = {H31A-1134}, language = {en} } @inproceedings{GerkeSchneiderMaureretal., author = {Gerke, Horst H. and Schneider, Anna and Maurer, Thomas and Raab, Thomas}, title = {Quantification and reconstruction of Initial 3D Sediment Mass Distribution in an Artificially-Created Catchment Area Using GOCAD}, series = {American Geophysical Union, Fall Meeting - Eos transactions}, volume = {90}, booktitle = {American Geophysical Union, Fall Meeting - Eos transactions}, number = {52, Suppl.}, abstract = {For systems such as soils or watersheds, the initial distribution of sediment mass and composition at the starting point of the development are mostly not well-known. The development of such systems, however, has frequently been assumed to depend on boundary and initial conditions including the solid phase. Here, an experimental watershed of about 6 ha surface area was artificially-created in order to imitate an initial stage just at the beginning of the geo-ecosystem development. However, sediment homogeneity could not be achieved for this large-scale field experiment, and the 3D spatial distribution of structures and components remained uncertain. The objective of this study was to quantify and reconstruct the initial sediment distribution and the first development stages using aerial photographs, point information, and a 3D model. The watershed was made of coarse-textured sediments of quaternary origin with a low permeable clay liner as the bottom boundary. A 2D horizontal digital elevation model (DEM) of the surface and a DEM of the subsurface clay layer are used to construct a 3D triangulated numerical grid of the catchment's initial spatial structure using the 3D-GIS software GOCAD. Physical and chemical soil properties obtained from borehole samples are assigned to this model and interpolated onto the 3D grid. The volumetric changes in space and time are quantified and related to material properties to obtain the mass changes. Correlations between terrain attributes, sediment properties, and mass changes are explored specifically in regions of differing source materials. A temporal sequence of surface DEMs is obtained from photogrammetric, high-precision ground based laser scanning and airborne laser scanning data. 3D models of elevation change are constructed from these DEMs. The processes following the initial state are mainly characterized by runoff-induced erosive mass relocations related to the distribution of surface and subsurface structures and sediment properties. The results suggest that both sediment structures and mass translocations differ between the western and eastern parts of the watershed and that correlations between initial surface structures and subsequent mass changes exist.}, 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{MaurerSchappBuechneretal., author = {Maurer, Thomas and Schapp, Andrea and B{\"u}chner, Steffen and Menzel, Hannes and Hinz, Christoph}, title = {Measurement of rainfall distribution on a small catchment for the evaluation of canopy interception effects}, series = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, booktitle = {European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April - 02 May 2014}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Variability of rainfall and throughfall is an essential characteristic of the water balance at spatial scales ranging from meters to hundreds of meters or even kilometers. The amount of throughfall is governed by the characteristics of the vegetation canopy and the involved interception and stemflow effects. In initial, developing ecosystems, distinct patterns of the growing vegetation (e.g. patchiness) supposedly govern the spatial distribution of water in the system, thereby initiating and supporting hydro-ecological feedback processes. Questions are i) is the spatial variability of vegetation relevant for the system as a whole, and ii) how does the distribution of the effective precipitation (i.e. the infiltration) change over time in dependency of vegetation succession? We present the first results of a spatially distributed measurement approach of surface-near precipitation on the constructed catchment "H{\"u}hnerwasser" ("Chicken Creek"). The 6-ha site is located in the recultivation area of the lignite open-cast mine "Welzow-S{\"u}d" in Lower Lusatia, Brandenburg, Germany. Here, the free development of an initial ecosystem is investigated since September 2005. After eight years of succession, the spatial distribution of plant species is highly heterogeneous, and gains increasing influence on throughfall patterns, thus impacting the distribution of soil humidity and possibly even surface runoff. For spatially distributed precipitation measurement, 47 tipping bucket rain gauges were installed in heights of 0.5 m and 1.0 m along two transects on the catchment. Rain gauge data were collected by a wireless sensor node network provided by the Sens4U joint research project. The transects run NW-SE and NE-SW and cover the range of plant communities presently existing in the ecosystem: locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens. The raw measurement data were temporally aggregated using a VBA script in order to characterize interception for various types of precipitation events on different time scales. First results from the measurement period 17th July - 3rd September 2013 widely exhibit a good accordance with reference data from on-site weather stations for sites on open ground, while canopy sites show more heterogeneous values, either due to interception or due to canopy collection effects. However, it was found that the explanation of the differences between comparable sites requires an additional inclusion of other relevant parameters, e.g. wind speed and direction, screening effects, and specific canopy characteristics. Moreover, extreme precipitation events sometimes seemed to lead to incorrect measurements either by the sensor and / or node, which required supplementary quality controls of equipment and data. Results from future long-term measurements on the "H{\"u}hnerwasser" catchment will be used to identify possible plant-soil feedback mechanisms and to parameterize models that simulate the behavior of initial eco-hydrological systems}, language = {de} } @inproceedings{MaurerTrujilloSiliezarOeseretal., author = {Maurer, Thomas and Trujillo Sili{\´e}zar, Carlos Gustavos and Oeser, Anne and Pohle, Ina and Hinz, Christoph}, title = {A methodology for investigating interdependencies between measured throughfall, meteorological variables and canopy structure on a small catchment}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {In evolving initial landscapes, vegetation development depends on a variety of feedback effects. One of the less understood feedback loops is the interaction between throughfall and plant canopy development. The amount of throughfall is governed by the characteristics of the vegetation canopy, whereas vegetation pattern evolution may in turn depend on the spatio-temporal distribution of throughfall. Meteorological factors that may influence throughfall, while at the same time interacting with the canopy, are e.g. wind speed, wind direction and rainfall intensity. Our objective is to investigate how throughfall, vegetation canopy and meteorological variables interact in an exemplary eco-hydrological system in its initial development phase, in which the canopy is very heterogeneous and rapidly changing. For that purpose, we developed a methodological approach combining field methods, raster image analysis and multivariate statistics. The research area for this study is the H{\"u}hnerwasser ('Chicken Creek') catchment in Lower Lusatia, Brandenburg, Germany, where after eight years of succession, the spatial distribution of plant species is highly heterogeneous, leading to increasingly differentiated throughfall patterns. The constructed 6-ha catchment offers ideal conditions for our study due to the rapidly changing vegetation structure and the availability of complementary monitoring data.Throughfall data were obtained by 50 tipping bucket rain gauges arranged in two transects and connected via a wireless sensor network that cover the predominant vegetation types on the catchment (locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens). The spatial configuration of the vegetation canopy for each measurement site was described via digital image analysis of hemispheric photographs of the canopy using the ArcGIS Spatial Analyst, GapLight and ImageJ software. Meteorological data from two on-site weather stations (wind direction, wind speed, air temperature, air humidity, insolation, soil temperature, precipitation) were provided by the 'Research Platform Chicken Creek'. Data were combined and multivariate statistical analysis (PCA, cluster analysis, regression trees) were conducted using the R-software to i) obtain statistical indices describing the relevant characteristics of the data and ii) to identify the determining factors for throughfall intensity. The methodology is currently tested and results will be presented. Preliminary evaluation of the image analysis approach showed only marginal, systematic deviation of results for the different software tools applied, which makes the developed workflow a viable tool for canopy characterization. Results from this study will have a broad spectrum of possible applications, for instance the development / calibration of rainfall interception models, the incorporation into eco-hydrological models, or to test the fault tolerance of wireless rainfall sensor networks.}, language = {en} } @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{MaurerPohleOeseretal., author = {Maurer, Thomas and Pohle, Ina and Oeser, Anne and Sieber, Andr{\´e} and Hinz, Christoph}, title = {Bestimmung der Zusammenh{\"a}nge zwischen Bestandsniederschlag, meteorologischen Variablen und Vegetationsstruktur in einem sich entwickelnden Einzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 34}, language = {de} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Dynamik der initialen ({\"o}ko-) hydrologischen Entwicklung - Modellierung von Anfangsbedingungen und Wasserfl{\"u}ssen in einem exemplarischen Einzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 20}, language = {de} } @inproceedings{MaurerPohleOeseretal., author = {Maurer, Thomas and Pohle, Ina and Oeser, Anne and Sieber, Andr{\´e} and Hinz, Christoph}, title = {Investigating the interrelations between throughfall, meteorological variables and vegetation structure in a developing hydrological catchment}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {In landscapes with heterogeneous vegetation structure, interception and throughfall patterns produce spatiotemporal variability of soil moisture. This variability is important for eco-hydrological processes, in particular on small spatial scales up to the catchment scale. Throughfall depends on vegetation structure, whereas vegetation development is presumably co-determined by the spatio-temporal distribution of throughfall itself. In addition to vegetation structure, meteorological factors like wind speed and rainfall intensity also have an impact on throughfall. The objective of this study is to quantify the influence of vegetation structure and meteorological variables on spatial (and in the long run the temporal) variability of throughfall. For that purpose, we developed an approach combining field methods, image analysis and multivariate statistics. The 6-ha constructed catchment ‚H{\"u}hnerwasser' (aka Chicken Creek, southern Brandenburg, Germany) offers ideal conditions for the investigation of eco-hydrological feedback processes. After more than 10 years of development, vegetation structure on the catchment is spatially heterogeneous and evolves through natural succession. Furthermore, complementary meteorological data are available on-site. Throughfall was measured using 50 tipping-bucket rain gauges, which are aligned along two transects in 0.5 and 1 m heights, covering the dominating vegetation types on the catchment (e.g., robinia, sallow thorn, reed, reedgrass, herbs). The spatial distribution of vegetation structures around each measurement site was recorded with hemispheric photographs, which were subsequently analyzed using image processing techniques. Two weather stations provide reference values for precipitation and relevant meteorological variables for wind speed and direction, air humidity, temperature and irradiation. The amount and distribution of precipitation measured in scarcely vegetated areas of the catchment widely correspond with values from the reference weather stations. Under dense vegetation, very heterogeneous values were recorded, which can be explained by i) canopy interception, and ii) fetching effects. The results of this study can serve as basis for interception models and may also contribute to complex eco-hydrological models.}, language = {en} } @inproceedings{MaurerCaviedesVoulliemeHinzetal., author = {Maurer, Thomas and Caviedes-Voulli{\`e}me, Daniel and Hinz, Christoph and Gerke, Horst H.}, title = {Flow processes on the catchment scale - modeling of initial structural states and hydrological behavior in an artificial exemplary catchment}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Landscapes that are heavily disturbed or newly formed by either natural processes or human activity are in a state of disequilibrium. Their initial development is thus characterized by highly dynamic processes under all climatic conditions. The primary distribution and structure of the solid phase (i.e. mineral particles forming the pore space) is one of the decisive factors for the development of hydrological behavior of the eco-hydrological system and therefore (co-) determining for its - more or less - stable final state. The artificially constructed ‚H{\"u}hnerwasser' catchment (a 6 ha area located in the open-cast lignite mine Welzow-S{\"u}d, southern Brandenburg, Germany) is a landscape laboratory where the initial eco-hydrological development is observed since 2005. The specific formation (or construction) processes generated characteristic sediment structures and distributions, resulting in a spatially heterogeneous initial state of the catchment. We developed a structure generator that simulates the characteristic distribution of the solid phase for such constructed landscapes. The program is able to generate quasi-realistic structures and sediment compositions on multiple spatial levels (1 cm up to ∼ 100 m scale). The generated structures can be i) conditioned to actual measurement values (e.g., soil texture and bulk distribution); ii) stochastically generated, and iii) calculated deterministically according to the geology and technical processes at the excavation site. Results are visualized using the GOCAD software package and the free software Paraview. Based on the 3D-spatial sediment distributions, effective hydraulic van-Genuchten parameters are calculated using pedotransfer functions. The hydraulic behavior of different sediment distribution (i.e. versions or variations of the catchment's porous body) is calculated using a numerical model developed by one of us (Caviedes-Voulli{\`e}me). Observation data are available from catchment monitoring are available for i) determining the boundary conditions (e.g., precipitation), and ii) the calibration / validation of the model (catchment discharge, ground water). The analysis of multiple sediment distribution scenarios should allow to approximately determine the influx of starting conditions on initial development of hydrological behavior. We present first flow modeling results for a reference (conditioned) catchment model and variations thereof. We will also give an outlook on further methodical development of our approach.}, language = {en} } @inproceedings{PohleNiebischZhaetal., author = {Pohle, Ina and Niebisch, Michael and Zha, Tingting and Sch{\"u}mberg, Sabine and M{\"u}ller, Hannes and Maurer, Thomas and Hinz, Christoph}, title = {A stochastical event-based continuous time step rainfall generator based on Poisson rectangular pulse and microcanonical random cascade models}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Rainfall variability within a storm is of major importance for fast hydrological processes, e.g. surface runoff, erosion and solute dissipation from surface soils. To investigate and simulate the impacts of within-storm variabilities on these processes, long time series of rainfall with high resolution are required. Yet, observed precipitation records of hourly or higher resolution are in most cases available only for a small number of stations and only for a few years. To obtain long time series of alternating rainfall events and interstorm periods while conserving the statistics of observed rainfall events, the Poisson model can be used. Multiplicative microcanonical random cascades have been widely applied to disaggregate rainfall time series from coarse to fine temporal resolution. We present a new coupling approach of the Poisson rectangular pulse model and the multiplicative microcanonical random cascade model that preserves the characteristics of rainfall events as well as inter-storm periods. In the first step, a Poisson rectangular pulse model is applied to generate discrete rainfall events (duration and mean intensity) and inter-storm periods (duration). The rainfall events are subsequently disaggregated to high-resolution time series (user-specified, e.g. 10 min resolution) by a multiplicative microcanonical random cascade model. One of the challenges of coupling these models is to parameterize the cascade model for the event durations generated by the Poisson model. In fact, the cascade model is best suited to downscale rainfall data with constant time step such as daily precipitation data. Without starting from a fixed time step duration (e.g. daily), the disaggregation of events requires some modifications of the multiplicative microcanonical random cascade model proposed by Olsson (1998): Firstly, the parameterization of the cascade model for events of different durations requires continuous functions for the probabilities of the multiplicative weights, which we implemented through sigmoid functions. Secondly, the branching of the first and last box is constrained to preserve the rainfall event durations generated by the Poisson rectangular pulse model. The event-based continuous time step rainfall generator has been developed and tested using 10 min and hourly rainfall data of four stations in North-Eastern Germany. The model performs well in comparison to observed rainfall in terms of event durations and mean event intensities as well as wet spell and dry spell durations. It is currently being tested using data from other stations across Germany and in different climate zones. Furthermore, the rainfall event generator is being applied in modelling approaches aimed at understanding the impact of rainfall variability on hydrological processes.}, language = {en} } @misc{RoeschSeidlitzPfeiferetal., author = {R{\"o}sch, Janina J. and Seidlitz, Holger and Pfeifer, Robin and Burlefinger, Hubert and Maurer, Thomas}, title = {Preform joints in embroidered fabrics - influence on the mechanical properties}, series = {Advanced Composite Materials}, journal = {Advanced Composite Materials}, pages = {1 -- 16}, abstract = {Preforms with large complex geometry, for example, body parts for the automotive industry, are consisted into multiple elements - so-called sub-preforms. Hereby the sub-preforms can be adjusted to different local load cases but joining of these sub-preforms also raises challenges. The preform joints are decisive to the mechanical properties of the final component. The state-of-the-art joint, a single lap, results in a variation of wall thickness with local redirection of fibre orientation. In this paper, the influence of alternative joints of embroidered fabrics is analysed regarding the resulting mechanical properties of the part. The built test specimen contains different preform joints with different process-relevant parameters. Such as gaps between the sub-preforms, to analyse the influence on the mechanical performance. To reveal the various defects like voids, air pockets and to validate the fibre orientation, computer tomography (CT) investigation was performed on the built plates. In addition, the influence in mechanical properties was also analysed. The overlapping is analysed with tensile strength test according to DIN EN ISO 527-4.}, 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} }