Climate and land use change effects on soil erosion in two small agricultural catchment systems Fugnitz - Austria, Can Revull - Spain.

Soil erosion represents one of the most important processes of land degradation in the world and is considered a serious threat to the provision of food supply, to human health and to terrestrial ecosystems. In Europe, soil erosion by water and tillage is responsible for the loss of fertile topsoil and therefore productive land. Under Global Change scenarios climate and land use are expected to impact soil loss and sediment discharge rates distinctly in contrasting climatic regions, further influenced by tillage practices. Soil erosion modeling is a valuable tool to estimate future changes and elucidate opportunities to mitigate future threats to soil loss and crop yield, ultimately leading to the development of Best Management Practices (BMPs). In this study, future change of soil erosion processes under the IPCC Representative Concentration Pathways RCP2.6 and RCP6.0, as well as a conventional tillage (CT) and a reduced tillage (RT) practice are investigated in two small agricultural catchments in Europe under contrasting climate; Can Revull in Spain and Fugnitz in Austria. We applied GeoWEPP, the Geospatial Interface for the Water Erosion Prediction Project, to model these two agricultural catchments at a fine spatial resolution. We demonstrate that tillage practice, precipitation and runoff are driving factors for soil erosion at both locations. Furthermore, we illustrate that tillage practices have a greater effect on soil erosion than climate change scenarios. RT could reduce soil erosion by more than 75% compared to CT practices. Under RCP6.0, future changes in runoff, hillslope soil loss and sediment discharge would be greater compared to RCP2.6, with different responses depending on the investigated climatic region. Linking soil erosion models on a fine spatial scale and with different management practices to downscaled global circulation models, can provide valuable input for the development of future BMPs to reduce soil loss in agricultural landscapes.