@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} } @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{MaurerSchneiderGerke, author = {Maurer, Thomas and Schneider, Anna and Gerke, Horst H.}, title = {Scenario-Based Three-Dimensional Distributed Sediment Structures for a Constructed Hydrological Catchment}, series = {Vadose zone journal}, volume = {12}, journal = {Vadose zone journal}, number = {4}, issn = {1539-1663}, doi = {10.2136/vzj2013.02.0047}, abstract = {Many processes in a developing catchment can only be fully understood if the spatial heterogeneity is adequately described. Process-based modeling allows reproducing specific key structural elements of catchments. Constructed catchments are ideal test objects because of the well-known spatial conditions. In our study, we (i) modeled the entire process chain of catchment construction, (ii) established a consistent sediment mass/ volume balance between the excavated outcrop and the generated catchment model, and (iii) provided consistent three-dimensional distributions of texture and bulk density for deriving soil hydraulic properties. Data are from the 6 ha H{\"u}hnerwasser catchment (Chicken Creek, Lower Lusatia, Germany), which was constructed from overburden sediments in an open-cast lignite mine. Uncertainty about the parent material origin was captured in a multiscenario approach based on a geological model of the outcrop site and the simulation of excavation procedures. Generated distributions are incorporated in a gridded threedimensional volume model (GOCAD), and results were evaluated by semivariogram analysis and by quantifying point-to-point deviations. Filling and compaction are modeled based on three-dimensional volume analysis and mass balances of dumped sediments. Heterogeneities reflect both the batch-wise sediment variation and the succession of excavated geological units. The scale of the generated spatial models can be adjusted for three-dimensional hydrological catchment modeling while three-dimensional sediment mass balances can be used for analyzing soil and ecosystem development processes.}, language = {en} } @misc{HerrmannJahnMaurer, author = {Herrmann, Ludger and Jahn, Reinhold and Maurer, Thomas}, title = {Mineral dust around Sahara - from source to sink. A review with emphasis on contributions of the German soil science community in the last twenty years}, series = {Journal of Plant Nutrition and Soil Science}, volume = {173}, journal = {Journal of Plant Nutrition and Soil Science}, number = {6}, issn = {1522-2624}, pages = {811 -- 821}, language = {en} } @misc{MaurerHerrmannStahr, author = {Maurer, Thomas and Herrmann, Ludger and Stahr, Karl}, title = {The effect of surface variability factors on wind-erosion susceptibility: A field study in SW Niger}, series = {Journal of Plant Nutrition and Soil Science}, volume = {172}, journal = {Journal of Plant Nutrition and Soil Science}, number = {6}, issn = {1522-2624}, doi = {10.1002/jpln.200800141}, pages = {798 -- 807}, language = {en} }