Description: Das Projekt "Physical Mechanisms of Soil Erosion: Modelling and Validation" wird vom Umweltbundesamt gefördert und von Ecole Polytechnique Federale de Lausanne (EPF), Institut d'Amenagement des Terres et des Eaux (IATE) durchgeführt. Soil erosion is a world-wide problem with both economic and environmental effects. Consequences include loss of arable land and sediment-derived impacts on receiving water bodies. Even relatively small amounts of erosion can exceed the soil generation rate. Soil sediments are potential pollutants of receiving waters as they reduce light penetration and carry chemical pollutants such as pesticides and phosphorus. Soil erosion can be considered at local and basin scales. Rain is often the main initiator of erosion; other mechanisms include sheet erosion, rilling and gullying. These are all inherently hillslope-scale processes, the mechanisms of which involve connections between rainfall and raindrop impact, water flow, shear stress at the surface of the soil, sediment entrainment and deposition, etc. Management of soil erosion needs to be considered at the basin scale while attenuation measures are local. Physical understanding of erosion is based on local scale processes. At this scale overland flow-borne sediments and rilling (small channels that can be removed relatively easily) are the most important mechanisms. Rills have the potential to form channels under conditions of continued erosion. In addition, rills form in areas of flow concentration and thus rills are much more serious for erosion than interrill areas. The long-term goal of this fundamental research is to develop and validate process-based models of erosion-derived sediment transport at the scale of an element in a discretized catchment model, along with accompanying transport and transformations of nutrients and pollutants. This project seeks to fill one of the fundamental gaps in knowledge: mechanistic modelling of sediment transport at the local scale within a catchment. The project will further develop the mechanistic hillslope-scale Hairsine-Rose erosion model. This model includes both overland flow and sediment dynamics, and has been found to predict well erosion experimental data. However, it involves mechanistic assumptions that need to be clarified, and in addition it needs to be applied to circumstances that are more representative of reality, rather than constrained laboratory conditions. Potential mechanisms that could have significant effects on erosion modelling include the effect of infiltration/redistribution within the soil and the role of specific erosional mechanisms such as re-entrainment of previously eroded material verses transport by raindrop impact. Other factors to be investigated and modelled are multiple rainfall events and the effect of variable stone cover. Experiments and modelling will provide the basis of ascertaining the importance of such mechanisms.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Schädlingsbekämpfungsmittel ? Pestizid ? Gerinne ? Wasserstraße ? Lausanne ? Beleuchtung ? Nährstoff ? Phosphor ? Skigebiet ? Umweltauswirkung ? Erosion ? Brunnen ? Oberflächenabfluss ? Main ? Material ? Infiltration ? Ackerrandstreifen ? Licht ? Stress ? Wirkung ? Regen ? Daten ? Einzugsgebiet ? Wasserströmung ? Ackerland ? Management ? Regen ? Wasserspeicher ? Deposition ? Sediment ? Wasser ? Boden ? Bewässerung ? Modellierung ? Schaden ? Wirkung ? Wasserkörper ? Sedimentdynamik ? Abdeckung ? Sedimenttransport ? Forschung ? Forschungseinrichtung ? Niederschlag ? Bebauung ? Bedarf ? Gewässer ? Schadstoff ? Verkehr ? Gestein ? Globale Aspekte ? Maßnahme ? OEKONOMISCH ? PROJEKT ? EXPERIMENT ? UMVERTEILUNG ? FORMBLAETTER ? BETRAG ? UNTER ? VERARBEITEN ? Fluss [Bewegung] ? VERBINDUNG ? GRUNDLAGE ? Konzentrat ? VERFRACHTUNG ? VERHAELTNIS ? BEWERTEN ? Vorfluter ? Vorgang ? ANGEWANDT ? WICHTIG ? MECHANISMEN ? ZUSCHUETTUNG ? DAUER ? RATIFIKATION ? EIN ? SONSTIG ? OBERFLAECHE ? OBERIRDISCH ? EINDRINGUNG ? Ablagerung ? SPEZIFISCH ? POTENZIAL ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2007-08-01 - 2010-07-31
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