数字地形分析技术在流域水文建模中的应用

Application of digital terrain analysis technology for watershed hydrological modeling

论述了如何在DEM基础上;;自动提取流域自然水系的原理、方法和流程.并以西苕溪中上游流域为例;;针对DEM精度、上游集水区面积阈值和下垫面地形的不同;;对所提取水系进行了比较;;得出适合类似地区的DEM精度和上游集水区面积阈值.表明在丘陵山地、高山区及地形坡度不小于3?的地区;;由DEM提取的流域自然水网具有很高的可靠性.

The paper describes the principles, methods and processes of automated extraction of natural stream networks of watershed from DEM. For example, in upper reach watershed of Xitiaoxi River, a raster DEM is used to de?ne surface drainage and extract the stream networks. Through a comparison of the stream networks delineated from different resolution DEMs, threshold values of high ?ow accumulation and terrain, exact resolution DEMs and threshold values are obtained suited to this area and the similar regions. In terms of the experimental results, it can be concluded that in the mountainous area, especially if the mean slope of a working area is no less than 3 degrees, the delineated stream networks would be reliable. It is an universal reference for hydrological modeling of other washy watersheds in the south-east area of China.