Extraction of Catchment River Network Information Based on Different Resolution DEM

Abstract

The principles and methods of automatic extraction of river network based on raster digital elevation model (DEM) were briefly introduced. The process to extract river network using the Arc Hydro Tools includes: depression filling, building flow direction matrix, building flow accumulation matrix, building river network. In order to study the effects of different resolution DEM on extraction of river network, Qing jiang River, for instance, the experiment results on the extraction of drainage network from the 10m, 90m, 160m resolution DEM data were compared. It can be concluded that on the Arc GIS platform, the best observable resolution is 90m, which's extraction results can both meet the requirements on the accuracy and efficiency. but in flat area deviation is existed in the extraction result. Therefore, from the overall automatic extraction of basin river network based on DEM is feasible.