tudy on Methods of Extracting Catchment Properties Based on Multi-source Information

• 1、Collage of Water Resources and Environment, Hohai University
• 2、Collage of Water Resources and Environment Hehai University

Abstract：Development of information techniques offers new chances and challenges to hydrology. Extracting catchment properties from geography information system, especially from digital elevation models has becoming so hot. While the extracted properties often be very different from natural for the resolution and information of DEM is limited, which effects on hydrologic simulation. Natural river system was added on DEM to extract catchment properties as controlling factor. And the properties gotten with methods before or after adding natural channels were compared. The results showed that extracting catchment properties from DEM under the controlling of natural channels improved the precision of properties in two aspects at least. Firstly, the larger errors of DEM coming from horizontal resolution were corrected mostly for the right main channel could be gotten with this method. Secondly, this method resolved the problem of extracting river network of pits and plains, and improved the precision of properties. It was compared with similar methods, too. As a result, this method was more exacter. The reason may be that original information of DEM was not modified during extracting catchment properties with this method.

Keywords： extracting catchment properties DEM multi-source information