基于DEM的黑龙江宾州河流域水系提取试验研究

基于数字高程模型(digital elevation models,DEM)提取河网及相关流域信息是数字水文研究中的热点问题。以东北黑土区宾州河流域为研究区域,采用5m分辨率的DEM作为研究数据,运用ArcGIS9.2中的Hydrology水文处理工具包(Arc Hydro Tools)提取研究区河网特征。研究结果表明,分别采用0.75,1.25,2,2.5,3.75和5km2的集水面积阈值提取流域河网特征时,不同集水面积阈值对确定主河道的空间位置影响较小,但提取的数字流域河网特征会发生较大变化。基于河网密度与集水面积阈值及河源密度与集水面积阈值的关系探讨了适宜的集水面积阈值确定方法,发现取集水面积阈值为2km2时提取的河网特征与实际水系特征基本吻合,精度达95%以上。因此,基于Arc Hydro Tools的流域特征自动提取是切实可行的。

DEM Based Extraction of River Networks in Binzhou River Basin of Heilongjiang Province

Extracting river network characteristics based on digital elevation model(DEM) is a hotspot in digital hydrology research.By taking Binzhou River basin in the black soil region of Northeast China as an example and using 5-meter resolution DEM as the data for study,river network features were extracted by applying Arc Hydro Tools in ArcGIS 9.2 version.Results showed that when different drainage networks were extracted by setting drainage area threshold value to be 0.75,1.25,2,2.5,3.75,and 5 km2,respectively,different threshold values had very little effect on spatial position of the main stream network,but extracted river network features of the digital watershed changed greatly.A method for setting a suitable threshold value was proposed based on the relation of source density/drainage density with drainage area threshold.It was found that when drainage area threshold was 2 km2,extracted river network features were basically consistent with actual drainage net features,with prediction accuracy reaching 95%.Therefore,automatic extraction of watershed features based on Arc Hydro Tools is feasible.