SOIL-EROSION ASSESSMENT AND SIMULATION BY MEANS OF SGEOS AND ANCILLARY DIGITAL DATA

Due to soil erosion processes fertile soils are washed out almost anyw here in the world. Soil erosion protection measures are necessary, esp ecially for food security reasons. This study uses the well-known Univ ersal Soil Loss Equation (USLE) to assess the long-term soil erosion i n a small catchment area and to simulate various soil protection alter natives. After completion at this test site the techniques can be appl ied for larger regions to detect areas that are most affected by soil erosion and to guide precisely the efficient soil erosion prevention m easures that proved to be valuable according to the computer simulatio n results. This raster-oriented study uses a very accurate multi-tempo ral land-use classification to determine the land-cover (C-factor). Th e other input variables have been determined from ancillary data (e.g. , digital elevation model and soil data). The compiled data layers of this geographical information system (GIS) allow the calculation of th e long-term soil erosion per pixel as well as inquiries about all data layers for every pixel. In addition to the resulting soil erosion ris k map it is possible to simulate soil protection measures with the com puter. This ensures that only the most effective ones are introduced t o the field.