SLOPE LENGTH CALCULATIONS FROM A DEM WITHIN ARC INFO GRID/

The Universal Soil Loss Equation has been used for a number of years t o predict soil erosion rates. One of the required inputs to this model is the cumulative downhill slope length. Calculation of this factor h as been the largest problem in using the USLE. The only necessary data for this calculation is a digital elevation model (DEM). DEMs have be en available for years and are frequently used within Geographical Inf ormation Systems (GIS), but until recently the GIS software has not be en robust enough to support the necessary calculations. This paper des cribes a method for calculating cumulative downhill slope length from a digital elevation model within the ARC/INFO GRID raster system.