【摘要】 本文介绍了一种从DEM中提取流域河网水系的实用方法。该方法首先对DEM进行预处理即洼地的确定、填充和平地的抬升;然后采用D8算法确定DEM中每一个栅格单元的水流方向,根据水流方向数据,计算每一个栅格单元的上游集水面积,再根据给定的阈值,得出河流栅格网络图,生成需要的水系。此外,以古佛河小流域为例进行了水系提取,其结果与实际水系几乎完全匹配。更多还原

【Abstract】 A practical method of extracting drainage network of watershed from DEM is introduced in this paper.The method,first,needs to pre-process DEM data that is depressions to be identified and filled and flat areas are lifted.And then the flow direction of every grid cell in the DEM is determined according to the D8 algorithms.Thirdly, the upstream catchment’s area of every grid cell can be calculated on the basis of the data of grid cell flow direction. Fourthly, based on a threshold value of upstream catchment’s area, the grid cells in river lines can be picked out.Finally, the drainage network is extracted.Otherwise,taken Gufo river as an example of extracting drainage network, the results are basically consistent with the factual drainage network.更多还原