with parameter extraction using automated methods will not significantly influence discharge calculations. The recommendation, therefore, is to move towards any of the automated methods of hydrologic parameter extraction. On- screen digitization of raster graphic maps for small and medium areas eliminates the need to work with DEMs. For large areas, however, DEMs are recommended for efficiency and precision.
The second observation is that discharge is most sensitive to curve number, and less sensitive to slope or longest flow path. Discharge is also sensitive to drainage area. However, this study shows that the error associated in calculating drainage area is small compared to the error associated with calculating curve number. Determining an accurate curve number will reduce lag time and discharge calculation errors. The recommendation that results from this study is to carefully evaluate soil type, vegetative cover, and land use in a given area to obtain as accurate a curve number as possible.