Digital elevation model for topographic parameterization of agricultural watershed of Gowai river catchment

摘要

Digital Elevation Model (DEM) is a raster representation of a conlinous surface, usually referring to the surface of the earth. This is a valuable tool for the topographic paramelerization of watersheds. In the present study DEM of 23m x 23m resolution was developed using ARC/INFO GIS software from contour map (1:25000 scale) of Banikdih agricultural watershed. Flow-direction and flow-accumulation themes were developed using depression less DEM. Finally, topographical parameters and stream (main channel and tributary channel) properties relating to land surface of watershed were extracted. The minimum and maximum values of slope were found to be 0% and 19 10% respectively. The minimum and maxium vales of aspect range (decimal degrees) were found tobe Flat (-1) and Northwest (337.50), respectively. The minimum and maximum vales of elevation were found to be 198.39m and 303.91m. Respectively. The total length of main and tributary channels was found to be 31720m and 56320m respectively. The averagevalues of slope, width and depth of main channel were found to 5.39%, 8.49m and 0.44m respectively, where as the average values of slope, width and depth of tributary channel were found to be 0.69%, 5.45m and 0.34m respectively.