基于DEM的延河流域水文特征提取与分析

基于DEM数据,依据地表径流漫流模拟算法,使用ArcGIS软件中的水文分析工具,提取与分析延河流域河网特征及相关信息,并与1∶25万地形图数字化水系进行分析比较。结果表明:集水面积阈值是决定河网提取精度的关键参数,阈值越大,提取河网越稀疏,反之则提取河网越密集;随着集水面积阈值的增大,河源数和河网密度、河流的级数、总河长等随之减少,但主河长变化不大;当阈值为5.51 km2时,提取河网与实际较吻合。因此,基于90m分辨率的DEM数据提取延河流域水系和子流域是切实可行的,可以作为数字流域建设与水资源管理的基础数据。

Extraction and analysis of hydrological characteristics of Yanhe watershed based on DEM

According to the algorithm for cross flow simulation of surface runoff combined with the tool of hydrological analysis in ArcGIS software,hydrological characteristics of river system in Yanhe watershed and related information were extracted based on the DEM data and were also compared with the digital water system on 1∶25 topographic maps.The results showed that the drainage water threshold was the key parameter for the extraction accuracy of water system,and the greater of drainage water threshold,the fewer and thinner of extracted water system;the smaller of drainage water threshold,the more concentrated of extracted water system vice verse.The number of river source,density of water system,class of river and the total river length decreased as drainage water threshold increased,but the main river length changed slightly.When threshold was 5.51 km2,water system extracted was relative coincident with the actual condition.Hydrological characteristics of river system in watershed and sub-watershed of Yanhe watershed were extracted based on the DEM data with 90 m resolution,which was feasible and could provide service for the construction of digital watershed and the management of basin water resources.