基于DEM提取流域河网研究

Research on extraction of stream network based on digital elevation models

回顾和介绍了基于DEM提取流域河网的三种不同算法:移动窗口算法、坡面径流模拟算法、谷线搜索算法,其中坡面径流模拟算法由于其水文学基础,能产生连续河网,能与分布式参数模型紧密结合,进而分析了这三种算法各自的优缺点和存在的主要问题,重点分析和讨论了坡面径流模拟算法中存在的三个基本问题:⑴水道起始点位置的确定,⑵凹陷与平坦区域水流方向的确定,⑶模拟河网与自然河网之间的偏差。最后,针对算法中存在的问题,探讨了未来的研究重点。

Three algorithms of automated extraction of stream network based on digital elevation models （DEMs） are introduced and reviewed. They are the moving windows algorithm, the flow of water over terrain algorithm and a valley line finding algorithm. The flow of water over terrain algorithm has become very widely used because it has a hydrological basis, can produce a continuous stream network, can be linked with distributed parameter models. Then the advantages and disadvantages of these three algorithms are compared and analyzed. Then the main problems are pointed out and discussed. Three main problems of flow of water over terrain algorithm： （a） the problem of positioning the ends of streams; （b） the problem of drainage direction assignment in flat areas and pits; （b） the problem of distinction between extracted stream network and natural stream network are discussed emphatically. Finally the future intensive research fields are pointed out according to the problems.