基于DEM的流域水文特征提取方法研究

运用GIS软件ArcGIS，以黄土丘陵沟壑区小流域为例，探讨了从数字高程模型（DEM）中提取流域水文特征的详细过程，包括：DEM的生成和预处理、水流方向的确定、流域汇流能力分析、河网的提取、流域边界的确定和子流域的划分。提出了基于DEM自动生成数字流域的一种方法，并将自动提取的流域与从地形图和遥感影像相结合手工提取的流域做了对比分析。结果表明，利用该方法提取的流域与利用手工方法提取的流域基本一致，平均误差为4．3％，从而证明该方法具有较高的精度。

Study on DEM-Based Basin Hydrologic Characteristic Extraction

The paper approaches the detailed process of hydrologic characteristic of the river basin extracted from digital elevation model(DEM),including DEM generating and pre-process,determination of flow direction,analysis of affluent capacity,extraction of hydrographic net,determination of river basin boundary and division of sub-basin by using ArcGIS software and taking small watersheds in gullied rolling loess area as an example.It puts forward a method of DEM-based automatic generating digital basin and conducts contrast and analysis between automatic extracted basin and manual extracted basin from the combination of topographic map and remote sensing images.The outcomes show that the river basin extracted by this method is basically the same as that manual extraction and the average error is 4.3%,showing high precision of the method.