A pragmatic approach for soil erosion risk assessment within policy hierarchies

This paper presents a methodological framework for scale-specific assessment of soil erosion by water. The framework enables the definition of hierarchical, functional and modular nested reference units which result from the integrated consideration of policy, process and model hierarchies. The framework is applied on three planning levels: at first, large scale zones are designated that show a defined risk potential for soil erosion (first level: catchments and drainage areas in the German Federal State of Saxony-Anhalt, ca. 20,000 km²). By both increasing model complexity and spatio-temporal resolution of input data, the results are locally specified within these risk zones (second level: designated farms and fields in a study area of 141 km²). This is the basis for the prediction of soil erosion areas and sediment transport to hydrologic drainage networks as well as for small scale management and measure planning (third level: designated field blocks in the study area). On this level, the mitigation of soil erosion and sediment entry to the river system is demonstrated by simulating the introduction of conservation management practices, vegetation and riparian buffer strips.