Research and extraction of the hydrological characteristics based on GIS and DEM

Introduced the principles and methods about extraction of water system and hydrology based on GIS and DEM, applied by the example. Selected Inner Mongolia Xilamuren grassland as the research object, used 1:50 000 scale, 10m resolution DEM which obtain from topographic maps as the basic terrain data, extraction and research water system and the hydrological characteristics based on the geographic information system software ArcGIS 9.3. The results showed that the use of regional or watershed DEM to extract water system, basin-wide hydrological information is high efficiency, less errors, it can completely meet the needs of hydrological modeling and production from macroscopic perspective. In some regions of special terrain, such as flat regions, the abstracting precision need to be further improved since parallel water system is likely to generate there.