Application of WEPP and GIS on small watersheds in USA and Austria

Geographic Information Systems (GIS) are well structured databases for handling large quantities of spatially varied data within a watershed. Coupling of a GIS with a spatially variable, physically-based, deterministic hydrological model such as the USDA-Water Erosion Prediction Project (WEPP) offers many advantages. The WEPP model is a new computer program based on the fundamentals of hydrology, soil physics, plant science, hydraulics, and erosion mechanics. The WEPP model provides several major advantages over existing hydrological and erosion models; for example, it reflects the effects of soil surface conditions due to agricultural, range and forestry practices on storm runoff and erosion. The Geographical Resources Analysis Support System (GRASS) GIS was used to obtain many of the needed input parameters for the WEPP computer model. The results indicate GRASS- GIS technology is a powerful tool and can be used to parameterize a complex hydrological model such as WEPP.