ABSTRACT:
Geographic information systems (GIS) are well-structured databases for handling large quantities of spatially varied data within a watershed. Linking of a GIS with a spatially, physically-based, deterministic hydrologic model such as the USDA-Water Erosion Prediction Project (WEPP) offers many advantages. The USDA-Water Erosion Prediction Project (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 hydrologic and erosion model; for example, it reficts the effects of soilsu face conditions due to agricultural, range, and foresty practices on storm runoff and erosion. Furthermore, it model spatial and temporal variability of the factors affecting the watershed hydrologic and erosion regime. The WEPP model requires hydrometeorological, soil, topography, and land-use data. The Geographical Resources Analysis Support System (GRASS) GIS was used to obtain many of the needed input parameters. The WEPP model was evaluated on a watershed in the Indian Pine Natural Resources Field Station near West Lafayette, Indiana. The model-predicted storm runoff was compared with measured values. The results indicate that GRASS-GIS technology is a powerful tool and can be used to parameterize a complex hydrologic model such as WEPP. The results also indicate that using GRASS-GIS maps to recognize watershed configurations and representative hillslopes improved the model's ability to predict storm runoff.
Footnotes
M. R. Savabi is a hydrologist and D. C. Flanagan is an agricultural engineer with the USDA-Agricultural Research Service, National Soil Erosion Research Laboratory, Purdue University, West Lafayette, IN; B. Hebel is a research associate, University for Renewable Resources, Institute for Hydraulics and Rural Water Resources Management, Vienna, Austria; B.A. Engel is an associate professor, Department of Agricultural Engineering, Purdue University, West Lafayette, IN. The data for model evaluation were provided by the staff of the Purdue University Animal Science Watershed Research Center.
- Copyright 1995 by the Soil and Water Conservation Society
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