Extraction of watershed characteristics of Red River based on SRTM DEM

Based on SRTM DEM data, Arc Hydro Tools of ArcGIS is firstly employed with Red River as an example in this paper. On the basis of D8 algorithm, the authors then confirm flow direction of raster units according to the steepest gradient as well as starting-point and end-point of river section by means of threshold catchments area. Next, searching for upstream water-supply district of each river section from sub-watershed exit, the boundaries of whole watershed and each sub-watershed are obtained, which will finish characteristics extracting and generate digital Red River watershed. Eventually, experiment result of watershed is analyzed.