This paper describes experiments of the use of topographic sketch method in the region of Sanchuan river basin

Shanxi province

this basin is a region of loess hilly ravine land. Better results can be obtained when following choices are employed: using the discrete cosine transformation facet; smaller window size; DEM from better resolution data.The experiment shows that the topographic sketch method is practicable for extraction of ravine network or basin network from DEM and able to use it for geographic information system.