@article{vanderMeijTemmeWallingaetal.2017,
  author    = {van der Meij, Marijn W. and Temme, Arnaud J. A. M. and Wallinga, J. and Hierold, W. and Sommer, Michael},
  title     = {Topography reconstruction of eroding landscapes - A case study from a hummocky ground moraine (CarboZALF-D)},
  series = {Geomorphology : an international journal on pure and applied geomorphology},
  volume    = {295},
  journal   = {Geomorphology : an international journal on pure and applied geomorphology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0169-555X},
  doi       = {10.1016/j.geomorph.2017.08.015},
  pages     = {758 -- 772},
  year      = {2017},
  abstract  = {Erosion processes, aggravated by human activity, have a large impact on the spatial variation of soil and topographic properties. Knowledge of the topography prior to human-induced erosion (paleotopography) in naturally stable landscapes is valuable for identifying vulnerable landscape positions and is required as starting point for erosion modelling exercises. However, developing accurate reconstructions of paleotopography provide a major challenge for geomorphologists. Here, we present a set of paleotopographies for a closed kettle hole catchment in north-east Germany (4 ha), obtained through different reconstruction approaches. Current soil and colluvium thickness, estimated from a dataset of 264 soil descriptions using Ordinary Kriging, were used as input for a mass balance, or were compared with a set of undisturbed soil thicknesses to estimate the amount of erosion. The performance of the different approaches was assessed with cross-validation and the count of mispredicted eroded, depositional or stable landscape positions. The paleotopographic reconstruction approach based on the average thickness of undisturbed soils in the study area showed the best performance. This thickness (1.00 m) is comparable to the average undisturbed soil thickness in the region and in line with global correlations of soil thickness as a function of rainfall and initial CaCO3 content. The performance of the different approaches depended more on mispredictions of landscape position due to the assumption of a spatially constant initial soil depth than on small variations in this depth. To conclude, we mention several methodological and practical points of attention for future topography reconstruction studies, concerning data quality and availability, spatial configuration of data and other processes affecting topography. (C) 2017 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@phdthesis{Rohrmann2015,
  author    = {Rohrmann, Alexander},
  title     = {The role of wind and water in shaping earth's plateaus},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77938},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XXV, 157},
  year      = {2015},
  abstract  = {The overarching goal of this dissertation is to provide a better understanding of the role of wind and water in shaping Earth's Cenozoic orogenic plateaus - prominent high-elevation, low relief sectors in the interior of Cenozoic mountain belts. In particular, the feedbacks between surface uplift, the build-up of topography and ensuing changes in precipitation, erosion, and vegetation patterns are addressed in light of past and future climate change. Regionally, the study focuses on the two world's largest plateaus, the Altiplano-Puna Plateau of the Andes and Tibetan Plateau, both characterized by average elevations of >4 km. Both plateaus feature high, deeply incised flanks with pronounced gradients in rainfall, vegetation, hydrology, and surface processes. These characteristics are rooted in the role of plateaus to act as efficient orographic barriers to rainfall and to force changes in atmospheric flow. The thesis examines the complex topics of tectonic and climatic forcing of the surface-process regime on three different spatial and temporal scales: (1) bedrock wind-erosion rates are quantified in the arid Qaidam Basin of NW Tibet over millennial timescales using cosmogenic radionuclide dating; (2) present-day stable isotope composition in rainfall is examined across the south-central Andes in three transects between 22° S and 28° S; these data are modeled and assessed with remotely sensed rainfall data of the Tropical Rainfall Measuring Mission and the Moderate Resolution Imaging Spectroradiometer; (3) finally, a 2.5-km-long Mio-Pliocene sedimentary record of the intermontane Angastaco Basin (25°45' S, 66°00' W) is presented in the context of hydrogen and carbon compositions of molecular lipid biomarker, and oxygen and carbon isotopes obtained from pedogenic carbonates; these records are compared to other environmental proxies, including hydrated volcanic glass shards from volcanic ashes intercalated in the sedimentary strata. There are few quantitative estimates of eolian bedrock-removal rates from arid, low relief landscapes. Wind-erosion rates from the western Qaidam Basin based on cosmogenic 10Be measurements document erosion rates between 0.05 to 0.4 mm/yr. This finding indicates that in arid environments with strong winds, hyperaridity, exposure of friable strata, and ongoing rock deformation and uplift, wind erosion can outpace fluvial erosion. Large eroded sediment volumes within the Qaidam Basin and coeval dust deposition on the Chinese Loess plateau, exemplify the importance of dust production within arid plateau environments for marine and terrestrial depositional processes, but also health issues and fertilization of soils. In the south-central Andes, the analysis of 234 stream-water samples for oxygen and hydrogen reveals that areas experiencing deep convective storms do not show the commonly observed patterns of isotopic fractionation and the expected co-varying relationships between oxygen and hydrogen with increasing elevation. These convective storms are formed over semi-arid intermontane basins in the transition between the broken foreland of the Sierras Pampeanas, the Eastern Cordillera, and the Puna Plateau in the interior of the orogen. Here, convective rainfall dominates the precipitation budget and no systematic stable isotope-elevation relationship exists. Regions to the north, in the transition between the broken foreland and the Subandean foreland fold-and-thrust belt, the impact of convection is subdued, with lower degrees of storminess and a stronger expected isotope-elevation relationship. This finding of present-day fractionation trends of meteoric water is of great importance for paleoenvironmental studies in attempts to use stable isotope relationships in the reconstruction of paleoelevations. The third part of the thesis focuses on the paleohydrological characteristics of the Mio-Pliocene (10-2 Ma) Angastaco Basin sedimentary record, which reveals far-reaching environmental changes during Andean uplift and orographic barrier formation. A precipitation- evapotranspiration record identifies the onset of a precipitation regime related to the South American Low Level Jet at this latitude after 9 Ma. Humid foreland conditions existed until 7 Ma, followed by orographic barrier uplift to the east of the present-day Angastaco Basin. This was superseded by rapid (~0.5 Myr) aridification in an intermontane basin, highlighting the effects of eastward-directed deformation. A transition in vegetation cover from a humid C3 forest ecosystem to semi-arid C4-dominated vegetation was coeval with continued basin uplift to modern elevations.},
  language  = {en}
}
@phdthesis{Thiede2005,
  author    = {Thiede, Rasmus Christoph},
  title     = {Tectonic and climatic controls on orogenic processes : the Northwest Himalaya, India},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-2281},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {The role of feedback between erosional unloading and tectonics controlling the development of the Himalaya is a matter of current debate. The distribution of precipitation is thought to control surface erosion, which in turn results in tectonic exhumation as an isostatic compensation process. Alternatively, subsurface structures can have significant influence in the evolution of this actively growing orogen. Along the southern Himalayan front new 40Ar/39Ar white mica and apatite fission track (AFT) thermochronologic data provide the opportunity to determine the history of rock-uplift and exhumation paths along an approximately 120-km-wide NE-SW transect spanning the greater Sutlej region of the northwest Himalaya, India. 40Ar/39Ar data indicate, consistent with earlier studies that first the High Himalayan Crystalline, and subsequently the Lesser Himalayan Crystalline nappes were exhumed rapidly during Miocene time, while the deformation front propagated to the south. In contrast, new AFT data delineate synchronous exhumation of an elliptically shaped, NE-SW-oriented ~80 x 40 km region spanning both crystalline nappes during Pliocene-Quaternary time. The AFT ages correlate with elevation, but show within the resolution of the method no spatial relationship to preexisting major tectonic structures, such as the Main Central Thrust or the Southern Tibetan Fault System. Assuming constant exhumation rates and geothermal gradient, the rocks of two age vs. elevation transects were exhumed at ~1.4 \&\#177;0.2 and ~1.1 \&\#177;0.4 mm/a with an average cooling rate of ~50-60 \&\#176;C/Ma during Pliocene-Quaternary time. The locus of pronounced exhumation defined by the AFT data coincides with a region of enhanced precipitation, high discharge, and sediment flux rates under present conditions. We therefore hypothesize that the distribution of AFT cooling ages might reflect the efficiency of surface processes and fluvial erosion, and thus demonstrate the influence of erosion in localizing rock-uplift and exhumation along southern Himalayan front, rather than encompassing the entire orogen.Despite a possible feedback between erosion and exhumation along the southern Himalayan front, we observe tectonically driven, crustal exhumation within the arid region behind the orographic barrier of the High Himalaya, which might be related to and driven by internal plateau forces. Several metamorphic-igneous gneiss dome complexes have been exhumed between the High Himalaya to the south and Indus-Tsangpo suture zone to the north since the onset of Indian-Eurasian collision ~50 Ma ago. Although the overall tectonic setting is characterized by convergence the exhumation of these domes is accommodated by extensional fault systems.Along the Indian-Tibetan border the poorly described Leo Pargil metamorphic-igneous gneiss dome (31-34\&\#176;N/77-78\&\#176;E) is located within the Tethyan Himalaya. New field mapping, structural, and geochronologic data document that the western flank of the Leo Pargil dome was formed by extension along temporally linked normal fault systems. Motion on a major detachment system, referred to as the Leo Pargil detachment zone (LPDZ) has led to the juxtaposition of low-grade metamorphic, sedimentary rocks in the hanging wall and high-grade metamorphic gneisses in the footwall. However, the distribution of new 40Ar/39Ar white mica data indicate a regional cooling event during middle Miocene time. New apatite fission track (AFT) data demonstrate that subsequently more of the footwall was extruded along the LPDZ in a brittle stage between 10 and 2 Ma with a minimum displacement of ~9 km. Additionally, AFT-data indicate a regional accelerated cooling and exhumation episode starting at ~4 Ma. Thus, tectonic processes can affect the entire orogenic system, while potential feedbacks between erosion and tectonics appear to be limited to the windward sides of an orogenic systems.},
  language  = {en}
}
@article{PenaAnguloNadalRomeroGonzalezHidalgoetal.2019,
  author    = {Pena-Angulo, D. and Nadal-Romero, E. and Gonzalez-Hidalgo, J. C. and Albaladejo, J. and Andreu, V and Bagarello, V and Barhi, H. and Batalla, R. J. and Bernal, S. and Bienes, R. and Campo, J. and Campo-Bescos, M. A. and Canatario-Duarte, A. and Canton, Y. and Casali, J. and Castillo, V and Cerda, Artemi and Cheggour, A. and Cid, Patricio and Cortesi, N. and Desir, G. and Diaz-Pereira, E. and Espigares, T. and Estrany, Joan and Fernandez-Raga, M. and Ferreira, Carla S. S. and Ferro, Vito and Gallart, Francesc and Gimenez, R. and Gimeno, E. and Gomez, J. A. and Gomez-Gutierrez, A. and Gomez-Macpherson, H. and Gonzalez-Pelayo, O. and Hueso-Gonzalez, P. and Kairis, O. and Karatzas, G. P. and Klotz, S. and Kosmas, C. and Lana-Renault, Noemi and Lasanta, T. and Latron, J. and Lazaro, R. and Le Bissonnais, Y. and Le Bouteiller, C. and Licciardello, F. and Lopez-Tarazon, Jos{\´e} Andr{\´e}s and Lucia, A. and Marin, C. and Marques, M. J. and Martinez-Fernandez, J. and Martinez-Mena, M. and Martinez-Murillo, J. F. and Mateos, L. and Mathys, N. and Merino-Martin, L. and Moreno-de las Heras, M. and Moustakas, N. and Nicolau, J. M. and Novara, A. and Pampalone, V and Raclot, D. and Rodriguez-Blanco, M. L. and Rodrigo-Comino, Jes{\´u}s and Romero-Diaz, A. and Roose, E. and Rubio, J. L. and Ruiz-Sinoga, J. D. and Schnabel, S. and Senciales-Gonzalez, J. M. and Simonneaux, V and Sole-Benet, A. and Taguas, E. and Taboada-Castro, M. M. and Taboada-Castro, M. T. and Todisco, Francesca and Ubeda, X. and Varouchakis, E. A. and Vericat, Damia and Wittenberg, L. and Zabaleta, A. and Zorn, M.},
  title     = {Spatial variability of the relationships of runoff and sediment yield with weather types throughout the Mediterranean basin},
  series = {Journal of hydrology},
  volume    = {571},
  journal   = {Journal of hydrology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-1694},
  doi       = {10.1016/j.jhydrol.2019.01.059},
  pages     = {390 -- 405},
  year      = {2019},
  abstract  = {Soil degradation by water is a serious environmental problem worldwide, with specific climatic factors being the major causes. We investigated the relationships between synoptic atmospheric patterns (i.e. weather types, WTs) and runoff, erosion and sediment yield throughout the Mediterranean basin by analyzing a large database of natural rainfall events at 68 research sites in 9 countries. Principal Component Analysis (PCA) was used to identify spatial relationships of the different WTs including three hydro-sedimentary variables: rainfall, runoff, and sediment yield (SY, used to refer to both soil erosion measured at plot scale and sediment yield registered at catchment scale). The results indicated 4 spatial classes of rainfall and runoff: (a) northern sites dependent on North (N) and North West (NW) flows; (b) eastern sites dependent on E and NE flows; (c) southern sites dependent on S and SE flows; and, finally, (d) western sites dependent on W and SW flows. Conversely, three spatial classes are identified for SY characterized by: (a) N and NE flows in northern sites (b) E flows in eastern sites, and (c) W and SW flows in western sites. Most of the rainfall, runoff and SY occurred during a small number of daily events, and just a few WTs accounted for large percentages of the total. Our results confirm that characterization by WT improves understanding of the general conditions under which runoff and SY occur, and provides useful information for understanding the spatial variability of runoff, and SY throughout the Mediterranean basin. The approach used here could be useful to aid of the design of regional water management and soil conservation measures.},
  language  = {en}
}
@phdthesis{Wulf2011,
  author    = {Wulf, Hendrik},
  title     = {Seasonal precipitation, river discharge, and sediment flux in the western Himalaya},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57905},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {Rainfall, snow-, and glacial melt throughout the Himalaya control river discharge, which is vital for maintaining agriculture, drinking water and hydropower generation. However, the spatiotemporal contribution of these discharge components to Himalayan rivers is not well understood, mainly because of the scarcity of ground-based observations. Consequently, there is also little known about the triggers and sources of peak sediment flux events, which account for extensive hydropower reservoir filling and turbine abrasion. We therefore lack basic information on the distribution of water resources and controls of erosion processes. In this thesis, I employ various methods to assess and quantify general characteristics of and links between precipitation, river discharge, and sediment flux in the Sutlej Valley. First, I analyze daily precipitation data (1998-2007) from 80 weather stations in the western Himalaya, to decipher the distribution of rain- and snowfall. Rainfall magnitude frequency analyses indicate that 40\% of the summer rainfall budget is attributed to monsoonal rainstorms, which show higher variability in the orogenic interior than in frontal regions. Combined analysis of rainstorms and sediment flux data of a major Sutlej River tributary indicate that monsoonal rainfall has a first order control on erosion processes in the orogenic interior, despite the dominance of snowfall in this region. Second, I examine the contribution of rainfall, snow and glacial melt to river discharge in the Sutlej Valley (s55,000 km2), based on a distributed hydrological model, which covers the period 2000-2008. To achieve high spatial and daily resolution despite limited ground-based observations the hydrological model is forced by daily remote sensing data, which I adjusted and calibrated with ground station data. The calibration shows that the Tropical Rainfall Measuring Mission (TRMM) 3B42 rainfall product systematically overestimates rainfall in semi-arid and arid regions, increasing with aridity. The model results indicate that snowmelt-derived discharge (74\%) is most important during the pre-monsoon season (April to June) whereas rainfall (56\%) and glacial melt (17\%) dominate the monsoon season (July-September). Therefore, climate change most likely causes a reduction in river discharge during the pre-monsoon season, which especially affects the orogenic interior. Third, I investigate the controls on suspended sediment flux in different parts of the Sutlej catchments, based on daily gauging data from the past decade. In conjunction with meteorological data, earthquake records, and rock strength measurements I find that rainstorms are the most frequent trigger of high-discharge events with peaks in suspended sediment concentrations (SSC) that account for the bulk of the suspended sediment flux. The suspended sediment flux increases downstream, mainly due to increases in runoff. Pronounced erosion along the Himalayan Front occurs throughout the monsoon season, whereas efficient erosion of the orogenic interior is confined to single extreme events. The results of this thesis highlight the importance of snow and glacially derived melt waters in the western Himalaya, where extensive regions receive only limited amounts of monsoonal rainfall. These regions are therefore particularly susceptible to global warming with major implications on the hydrological cycle. However, the sediment discharge data show that infrequent monsoonal rainstorms that pass the orographic barrier of the Higher Himalaya are still the primary trigger of the highest-impact erosion events, despite being subordinate to snow and glacially-derived discharge. These findings may help to predict peak sediment flux events and could underpin the strategic development of preventative measures for hydropower infrastructures.},
  language  = {en}
}
@phdthesis{Kuhnert2009,
  author    = {Kuhnert, Matthias},
  title     = {Quantifizierung von Oberfl{\"a}chenabfluss und Erosion auf B{\"o}den mit hydrophoben Eigenschaften},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32871},
  school      = {Universit{\"a}t Potsdam},
  year      = {2009},
  abstract  = {Die Zielsetzung der vorliegenden Arbeit ist die Beschreibung hydrophober Bodeneigenschaften und deren Auswirkungen auf Oberfl{\"a}chenabfluss und Erosion auf verschiedenen Skalen. Die dazu durchgef{\"u}hrten Untersuchungen fanden auf einer Rekultivierungsfl{\"a}che im Braunkohlegebiet Welzow S{\"u}d (S{\"u}dostdeutschland) statt. Die Prozesse wurden auf drei Skalen untersucht, die von der Plotskala (1m²) {\"u}ber die Hangskala (300m²) bis zur Betrachtung eines kleinen Einzugsgebietes (4ha) reichen. Der Grad der hydrophoben Bodeneigenschaften wurde sowohl direkt, {\"u}ber die Bestimmung des Kontaktwinkel, als auch indirekt, {\"u}ber die Bestimmung der Persistenz, ermittelt. Dabei zeigte sich, dass der Boden im Winterhalbjahr hydrophil reagierte, w{\"a}hrend er im Sommerhalbjahr hydrophobe Bodeneigenschaften aufwies. Die Ergebnisse deuten darauf hin, dass ansteigende Bodenwassergehalte, die in der Literatur h{\"a}ufig als Ursache f{\"u}r einen Wechsel der Bodeneigenschaften angegeben werden, auf dieser Fl{\"a}che nicht zu einem Umbruch der Bodenbedingungen f{\"u}hren. Stattdessen kam es als Folge des Auftauens von gefrorenem Boden zu hydrophilen Bodeneigenschaften, die zu einem Anstieg des Bodenwassergehalts f{\"u}hrten. R{\"a}umliche Unterschiede zeigten sich in den geomorphologischen Einheiten. Rinnen und Rillen wiesen seltener hydrophobe Eigenschaften als die Zwischenrillenbereiche und Kuppen auf. Diese r{\"a}umlichen und zeitlichen Variabilit{\"a}ten wirkten sich auch auf den Oberfl{\"a}chenabfluss aus, der als Abflussbeiwert (ABW: Quotient aus Abfluss und Niederschlag) untersucht wurde. Der ABW liegt auf B{\"o}den mit hydrophoben Bodeneigenschaften (ABW=0,8) deutlich h{\"o}her als bei jenen mit hydrophilen Eigenschaften(ABW=0,2), wie sie im Winter oder auf anderem Substrat vorzufinden sind (diese Werte beziehen sich auf die Plotskala). Betrachtet man die Auswirkungen auf unterschiedlichen Skalen, nimmt der Abflussbeiwert mit zunehmender Fl{\"a}chengr{\"o}ße ab (ABW = 0,8 auf der Plotskala, ABW = 0,5 auf der Hangskala und ABW = 0,2 im gesamten Gebiet), was in den hydrophil reagierenden Rillen und Rinnen auf der Hangskala und dem hydrophilen Substrat im Einzugsgebiet begr{\"u}ndet ist. Zur Messung der Erosion wurden verschiedene, zum Teil neu entwickelte Methoden eingesetzt, um eine hohe zeitliche und r{\"a}umliche Aufl{\"o}sung zu erreichen. Bei einer neu entwickelten Methode wird der Sedimentaustrag ereignisbezogen {\"u}ber eine Waage bestimmt. In Kombination mit einer Kippwaage erm{\"o}glicht sie die gleichzeitige Messung des Oberfl{\"a}chenabflusses. Die Messapparatur wurde f{\"u}r Gebiete entwickelt, die eine {\"u}berwiegend grobsandige Textur aufweisen und nur geringe Mengen Ton und Schluff enthalten. Zus{\"a}tzlich wurden zwei Lasersysteme zur Messung der r{\"a}umlichen Verteilung der Erosion eingesetzt. F{\"u}r die erste Methode wurde ein punktuell messender Laser in einer fest installierten Apparatur {\"u}ber die Fl{\"a}che bewegt und punktuell H{\"o}henunterschiede in einem festen Raster bestimmt. Durch Interpolation konnten Bereiche mit Sedimentabtrag von Akkumulationsbereiche unterschieden werden. Mit dieser Methode k{\"o}nnen auch gr{\"o}ßere Fl{\"a}chen vermessen werden (hier 16 m²), allerdings weisen die Messungen in den {\"U}bergangsbereichen von Rinne zu Zwischenrille große Fehler auf. Bei der zweiten Methode wird mit einer Messung ein Quadratmeter mit einer hohen r{\"a}umlichen Aufl{\"o}sung komplett erfasst. Um ein dreidimensionales Bild zu erstellen, m{\"u}ssen insgesamt vier Aufnahmen von jeweils unterschiedlichen Seiten aufgenommen werden. So lassen sich Abtrag und Akkumulation sehr genau bestimmen, allerdings ist die Messung relativ aufwendig und erfasst nur eine kleine Fl{\"a}che. Zus{\"a}tzlich wurde der Sedimentaustrag noch auf der Plotskala erfasst. Die Messungen zeigen, korrespondierend zu den Bodeneigenschaften, große Sedimentaustr{\"a}ge w{\"a}hrend des Sommerhalbjahrs und kaum Austr{\"a}ge im Winter. Weiterhin belegen die Ergebnisse eine gr{\"o}ßere Bedeutung der Rillenerosion gegen{\"u}ber der Zwischenrillenerosion f{\"u}r Niederschlagsereignisse hoher Intensit{\"a}t (>25 mm/h in einem zehnmin{\"u}tigem Intervall). Im Gegensatz dazu dominierte die Zwischenrillenerosion bei Ereignissen geringerer Intensit{\"a}t (<20 mm/h in einem zehnmin{\"u}tigem Intervall), wobei mindestens 9 mm Niederschlag in einer Intensit{\"a}t von mindesten 3,6 mm/h n{\"o}tig sind, damit es zur Erosion kommt. Basierend auf den gemessenen Abfl{\"u}ssen und Sedimentaustr{\"a}gen wurden Regressiongleichungen abgeleitet, die eine Berechnung dieser beiden Prozesse f{\"u}r die untersuchte Fl{\"a}che erm{\"o}glichen. W{\"a}hrend die Menge an Oberfl{\"a}chenabfluss einen starken Zusammenhang zu der Menge an gefallenem Niederschlag zeigt (r² = 0,9), ist die Berechnung des ausgetragenen Sedimentes eher ungenau (r² = 0,7). Zusammenfassend beschreibt die Arbeit Einfl{\"u}sse hydrophober Bodeneigenschaften auf verschiedenen Skalen und arbeitet die Auswirkungen, die vor allem auf der kleinen Skala von großer Bedeutung sind, heraus.},
  language  = {de}
}
@article{BronstertdeAraujoBatallaVillanuevaetal.2014,
  author    = {Bronstert, Axel and de Araujo, Jose-Carlos and Batalla Villanueva, Ramon J. and Costa, Alexandre Cunha and Delgado, Jos{\´e} Miguel Martins and Francke, Till and F{\"o}rster, Saskia and Guentner, Andreas and Lopez-Tarazon, Jos{\´e} Andr{\´e}s and Mamede, George Leite and Medeiros, Pedro Henrique Augusto and Mueller, Eva and Vericat, Damia},
  title     = {Process-based modelling of erosion, sediment transport and reservoir siltation in mesoscale semi-arid catchments},
  series = {Journal of soils and sediments : protection, risk assessment and remediation},
  volume    = {14},
  journal   = {Journal of soils and sediments : protection, risk assessment and remediation},
  number    = {12},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1439-0108},
  doi       = {10.1007/s11368-014-0994-1},
  pages     = {2001 -- 2018},
  year      = {2014},
  abstract  = {To support scientifically sound water management in dryland environments a modelling system has been developed for the quantitative assessment of water and sediment fluxes in catchments, transport in the river system, and retention in reservoirs. The spatial scale of interest is the mesoscale because this is the scale most relevant for management of water and land resources. This modelling system comprises process-oriented hydrological components tailored for dryland characteristics coupled with components comprising hillslope erosion, sediment transport and reservoir deposition processes. The spatial discretization is hierarchically designed according to a multi-scale concept to account for particular relevant process scales. The non-linear and partly intermittent run-off generation and sediment dynamics are dealt with by accounting for connectivity phenomena at the intersections of landscape compartments. The modelling system has been developed by means of data from nested research catchments in NE-Spain and in NE-Brazil. In the semi-arid NE of Brazil sediment retention along the topography is the main process for sediment retention at all scales, i.e. the sediment delivery is transport limited. This kind of deposition retains roughly 50 to 60 \% of eroded sediment, maintaining a similar deposition proportion in all spatial scales investigated. On the other hand, the sediment retained in reservoirs is clearly related to the scale, increasing with catchment area. With increasing area, there are more reservoirs, increasing the possibility of deposition. Furthermore, the area increase also promotes an increase in flow volume, favouring the construction of larger reservoirs, which generally overflow less frequently and retain higher sediment fractions. The second example comprises a highly dynamic Mediterranean catchment in NE-Spain with nested sub-catchments and reveals the full dynamics of hydrological, erosion and deposition features. The run-off modelling performed well with only some overestimation during low-flow periods due to the neglect of water losses along the river. The simulated peaks in sediment flux are reproduced well, while low-flow sediment transport is less well captured, due to the disregard of sediment remobilization in the riverbed during low flow. This combined observation and modelling study deepened the understanding of hydro-sedimentological systems characterized by flashy run-off generation and by erosion and sediment transport pulses through the different landscape compartments. The connectivity between the different landscape compartments plays a very relevant role, regarding both the total mass of water and sediment transport and the transport time through the catchment.},
  language  = {en}
}
@phdthesis{Hoffmann2016,
  author    = {Hoffmann, Bernd},
  title     = {Plant organic matter mobilization and export in fluvial systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99336},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiii, 131},
  year      = {2016},
  abstract  = {The global carbon cycle is closely linked to Earth's climate. In the context of continuously unchecked anthropogenic CO₂ emissions, the importance of natural CO₂ bond and carbon storage is increasing. An important biogenic mechanism of natural atmospheric CO₂ drawdown is the photosynthetic carbon fixation in plants and the subsequent longterm deposition of plant detritus in sediments. The main objective of this thesis is to identify factors that control mobilization and transport of plant organic matter (pOM) through rivers towards sedimentation basins. I investigated this aspect in the eastern Nepalese Arun Valley. The trans-Himalayan Arun River is characterized by a strong elevation gradient (205 - 8848 m asl) that is accompanied by strong changes in ecology and climate ranging from wet tropical conditions in the Himalayan forelad to high alpine tundra on the Tibetan Plateau. Therefore, the Arun is an excellent natural laboratory, allowing the investigation of the effect of vegetation cover, climate, and topography on plant organic matter mobilization and export in tributaries along the gradient. Based on hydrogen isotope measurements of plant waxes sampled along the Arun River and its tributaries, I first developed a model that allows for an indirect quantification of pOM contributed to the mainsetm by the Arun's tributaries. In order to determine the role of climatic and topographic parameters of sampled tributary catchments, I looked for significant statistical relations between the amount of tributary pOM export and tributary characteristics (e.g. catchment size, plant cover, annual precipitation or runoff, topographic measures). On one hand, I demonstrated that pOMsourced from the Arun is not uniformly derived from its entire catchment area. On the other, I showed that dense vegetation is a necessary, but not sufficient, criterion for high tributary pOM export. Instead, I identified erosion and rainfall and runoff as key factors controlling pOM sourcing in the Arun Valley. This finding is supported by terrestrial cosmogenic nuclide concentrations measured on river sands along the Arun and its tributaries in order to quantify catchment wide denudation rates. Highest denudation rates corresponded well with maximum pOM mobilization and export also suggesting the link between erosion and pOM sourcing. The second part of this thesis focusses on the applicability of stable isotope records such as plant wax n-alkanes in sediment archives as qualitative and quantitative proxy for the variability of past Indian Summer Monsoon (ISM) strength. First, I determined how ISM strength affects the hydrogen and oxygen stable isotopic composition (reported as δD and δ18O values vs. Vienna Standard Mean Ocean Water) of precipitation in the Arun Valley and if this amount effect (Dansgaard, 1964) is strong enough to be recorded in potential paleo-ISM isotope proxies. Second, I investigated if potential isotope records across the Arun catchment reflect ISM strength dependent precipitation δD values only, or if the ISM isotope signal is superimposed by winter precipitation or glacial melt. Furthermore, I tested if δD values of plant waxes in fluvial deposits reflect δD values of environmental waters in the respective catchments. I showed that surface water δD values in the Arun Valley and precipitation δD from south of the Himalaya both changed similarly during two consecutive years (2011 \& 2012) with distinct ISM rainfall amounts (~20\% less in 2012). In order to evaluate the effect of other water sources (Winter-Westerly precipitation, glacial melt) and evapotranspiration in the Arun Valley, I analysed satellite remote sensing data of rainfall distribution (TRMM 3B42V7), snow cover (MODIS MOD10C1), glacial coverage (GLIMSdatabase, Global Land Ice Measurements from Space), and evapotranspiration (MODIS MOD16A2). In addition to the predominant ISM in the entire catchment I found through stable isotope analysis of surface waters indications for a considerable amount of glacial melt derived from high altitude tributaries and the Tibetan Plateau. Remotely sensed snow cover data revealed that the upper portion of the Arun also receives considerable winter precipitation, but the effect of snow melt on the Arun Valley hydrology could not be evaluated as it takes place in early summer, several months prior to our sampling campaigns. However, I infer that plant wax records and other potential stable isotope proxy archives below the snowline are well-suited for qualitative, and potentially quantitative, reconstructions of past changes of ISM strength.},
  language  = {en}
}
@phdthesis{Schroeder2015,
  author    = {Schr{\"o}der, Sarah},
  title     = {Modelling surface evolution coupled with tectonics},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90385},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 129},
  year      = {2015},
  abstract  = {This study presents the development of 1D and 2D Surface Evolution Codes (SECs) and their coupling to any lithospheric-scale (thermo-)mechanical code with a quadrilateral structured surface mesh. Both SECs involve diffusion as approach for hillslope processes and the stream power law to reflect riverbed incision. The 1D SEC settles sediment that was produced by fluvial incision in the appropriate minimum, while the supply-limited 2D SEC DANSER uses a fast filling algorithm to model sedimantation. It is based on a cellular automaton. A slope-dependent factor in the sediment flux extends the diffusion equation to nonlinear diffusion. The discharge accumulation is achieved with the D8-algorithm and an improved drainage accumulation routine. Lateral incision enhances the incision's modelling. Following empirical laws, it incises channels of several cells width. The coupling method enables different temporal and spatial resolutions of the SEC and the thermo-mechanical code. It transfers vertical as well as horizontal displacements to the surface model. A weighted smoothing of the 3D surface displacements is implemented. The smoothed displacement vectors transmit the deformation by bilinear interpolation to the surface model. These interpolation methods ensure mass conservation in both directions and prevent the two surfaces from drifting apart. The presented applications refer to the evolution of the Pamir orogen. A calibration of DANSER's parameters with geomorphological data and a DEM as initial topography highlights the advantage of lateral incision. Preserving the channel width and reflecting incision peaks in narrow channels, this closes the huge gap between current orogen-scale incision models and observed topographies. River capturing models in a system of fault-bounded block rotations reaffirm the importance of the lateral incision routine for capturing events with channel initiation. The models show a low probability of river capturings with large deflection angles. While the probability of river capturing is directly depending on the uplift rate, the erodibility inside of a dip-slip fault speeds up headward erosion along the fault: The model's capturing speed increases within a fault. Coupling DANSER with the thermo-mechanical code SLIM 3D emphasizes the versatility of the SEC. While DANSER has minor influence on the lithospheric evolution of an indenter model, the brittle surface deformation is strongly affected by its sedimentation, widening a basin in between two forming orogens and also the southern part of the southern orogen to south, east and west.},
  language  = {en}
}
@misc{Mathaj2007,
  type      = {Master Thesis},
  author    = {Mathaj, Martin},
  title     = {Modellierung von Vegetationsentwicklung und Erosion entlang eines Klimagradienten von mediterran bis semiarid},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-27863},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {In dieser Arbeit wurde ein Modell mit einem gitterbasierten Ansatz entwickelt, um im Mediterranen entlang eines Klimagradienten Auswirkungen zu untersuchen, die Klima, Exposition, Hangneigung sowie St{\"o}rungen durch Feuer und Beweidung auf die Vegetations und Erosionsentwicklung besitzen. F{\"u}r die Fragestellung wurden Vegetationsalgorithmen benutzt. In dieser Studie verwendet wurden allgemeine Oberfl{\"a}chenprozesse, wie Wasser- und Sedimenttransport, die durch physikalische und empirische Modelle beschrieben worden sind. Des Weiteren wurde ein Sedimentverlust mit Hilfe der USLE kalkuliert, um ein Vergleich zwischen verschiedenen Erosionsans{\"a}tzen herzustellen. Die Vegetationsentwicklung und Erosion der mediterranen Gebiete konnte mit diesem Modell gut abgebildet werden. F{\"u}r die Vegetation der verschiedenen Klimagebiete und Habitate erwiesen sich die Wasserverf{\"u}gbarkeit und die Infiltrationsrate als maßgeblich. Die Erosion wurde vor allem durch einzelne heftige Niederschlagsereignisse beeinflusst. Dabei war vor allem am Hang und an steilen Neigungen ein hohes Erosionspotential gegeben. St{\"o}rungen durch Beweidung wirkten negativ auf die Vegetation und verst{\"a}rkten die Erosion. Feuer beeinflusste die Vegetations- und Erosionsentwicklung nur geringf{\"u}gig und ist somit zu vernachl{\"a}ssigen. Verschiedene B{\"o}den mit unterschiedlichen Texturen wiesen ein sehr unterschiedliches Erosionsverhalten auf. Dabei wiesen mittlere Korndurchmesser des Oberbodens von 0,02 bis 0,2 mm die h{\"o}chste Erosion auf. Die Vegetationsentwicklung wurde hingegen von der Bodentextur nicht beeinflust. Der Vergleich der Erosion berechnet durch die USLE und den Transportratenansatz verdeutlichte, dass die mittlere Erosion sehr {\"a}hnlich ausf{\"a}llt. Die USLE wies weniger Variabilit{\"a}t in der Erosion auf und ben{\"o}tigte zudem recht detaillierte Bodendaten. Der Ansatz gerade f{\"u}r die Erosionsberechnung in Form der Transportrate zeigte ein gutes Vorhersagepotential auf. In sehr variablen Umwelten ist diese Methode gegen{\"u}ber konservativen Erosionsmodellen zu bevorzugen, da interanuelle Dynamiken miterfasst werden, wie der Vergleich mit der USLE in der Studie gezeigt hatte. Mit Hilfe des Ansatzes der Transportrate besteht die M{\"o}glichkeit, Vorhersagen {\"u}ber Erosion {\"o}konomisch und effizient zu gestalten.},
  language  = {de}
}