@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} } @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} } @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} } @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} } @misc{MaurerHerrmannStahr, author = {Maurer, Thomas and Herrmann, Ludger and Stahr, Karl}, title = {Wind erosion charcteristics of Sahelian surface types}, series = {Earth Surface Processes and Landforms}, volume = {35}, journal = {Earth Surface Processes and Landforms}, number = {12}, issn = {1096-9837}, pages = {1386 -- 1401}, language = {en} } @misc{PohleNiebischMuelleretal., author = {Pohle, Ina and Niebisch, Michael and M{\"u}ller, Hannes and Sch{\"u}mberg, Sabine and Zha, Tingting and Maurer, Thomas and Hinz, Christoph}, title = {Coupling Poisson rectangular pulse and multiplicative microcanonical random cascade models to generate subdaily precipitation time series}, series = {Journal of Hydrology}, volume = {562}, journal = {Journal of Hydrology}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2018.04.063}, pages = {50 -- 70}, abstract = {To simulate the impacts of within-storm rainfall variabilities on fast hydrological processes, long precipi-tation time series with high temporal resolution are required. Due to limited availability of observed data such time series are typically obtained from stochastic models. However, most existing rainfall models are limited in their ability to conserve rainfall event statistics which are relevant for hydrological pro-cesses. Poisson rectangular pulse models are widely applied to generate long time series of alternating precipitation events durations and mean intensities as well as interstorm period durations. Multiplicative microcanonical random cascade (MRC) models are used to disaggregate precipitation time series from coarse to fine temporal resolution. To overcome the inconsistencies between the temporal structure of the Poisson rectangular pulse model and the MRC model, we developed a new coupling approach by introducing two modifications to the MRC model. These modifications comprise (a) a modified cascade model ("constrained cascade") which preserves the event durations generated by the Poisson rectangular model by constraining the first and last interval of a precipitation event to contain precipitation and (b) continuous sigmoid func-tions of the multiplicative weights to consider the scale-dependency in the disaggregation of precipita-tion events of different durations. The constrained cascade model was evaluated in its ability to dis-aggregate observed precipitation events in comparison to existing MRC models. For that, we used a 20-year record of hourly precipitation at six stations across Germany. The constrained cascade model showed a pronounced better agreement with the observed data in terms of both the temporal pattern of the precipitation time series (e.g. the dry and wet spell durations and autocorrelations) and event char-acteristics (e.g. intra-event intermittency and intensity fluctuation within events). The constrained cas-cade model also slightly outperformed the other MRC models with respect to the intensity-frequency relationship. To assess the performance of the coupled Poisson rectangular pulse and constrained cascade model, precipitation events were stochastically generated by the Poisson rectangular pulse model and then disaggregated by the constrained cascade model. We found that the coupled model performs satisfac-torily in terms of the temporal pattern of the precipitation time series, event characteristics and the in-tensity-frequency relationship.}, language = {en} } @misc{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water Balance Dynamics during Ten Years of Ecological Development at Chicken Creek Catchment}, series = {Vadose Zone Journal}, volume = {16}, journal = {Vadose Zone Journal}, number = {11}, issn = {1539-1663}, doi = {10.2136/vzj2017.04.0074}, pages = {14}, abstract = {Difficulties in quantitatively closing the water balance of catchments arise when upscaling point measurements and from insufficient knowledge of the physical boundaries, inner structure, and storage volumes of natural catchments. In addition, there is a strong need for generalizing the relationship between catchment characteristics and hydrological response. Therefore, experimental catchments with well-known boundaries and conditions could contribute valuable data to hydrological and critical zone research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha including a pond, Brandenburg, Germany) representing an initial ecosystem undergoing highly dynamic ecological development starting from clearly defined starting conditions. Directly after completion of the construction, extensive monitoring equipment was installed to track the ecosystem development and to capture the spatiotemporal variability of meteorological, hydrological, ecological, and soil conditions and vegetation succession. In this study, we focused on the water balance dynamics of the Chicken Creek catchment for the period 2005 to 2015 as influenced by ecological development. Water storage in the catchment was calculated from a three-dimensional model of groundwater volumes, soil moisture measurements, and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Time series of meteorological, hydrological, and ecological data for 10 yr enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology.}, language = {en} } @misc{SchneiderGerkeMaurer, author = {Schneider, Anna and Gerke, Horst H. and Maurer, Thomas}, title = {3D initial sediment distribution and quantification of mass balances of an artificially-created hydrological catchment based on DEMs from aerial photographs using GOCAD}, series = {Physics and Chemistry of the Earth}, volume = {36}, journal = {Physics and Chemistry of the Earth}, number = {1-4}, issn = {1474-7065}, doi = {10.1016/j.pce.2010.03.023}, pages = {87 -- 100}, language = {en} } @misc{MaurerSchneiderGerke, author = {Maurer, Thomas and Schneider, Anna and Gerke, Horst H.}, title = {A structure generator for modelling the initial sediment distribution of an artificial hydrologic catchment}, series = {Hydrology and earth system sciences}, volume = {15}, journal = {Hydrology and earth system sciences}, number = {12}, issn = {1607-7938}, pages = {3617 -- 3638}, language = {en} }