资源环境科技发展态势分析平台

Channel network identification is an important practice in not also hydrologic analysis but also hydraulic computation. In this paper, a new algorithm, watershed‐merging, is proposed to automatically identify and extract channel networks. In the water‐merging algorithm, based on the fact that the sink cell of a dendritic watershed is either a depression cell or a flat cell, a macro scale approach is proposed to treat the depression and flat areas (DAFA) and determine the flow direction within those areas, where the conventional D8 slope calculation fails. The separated neighboring watersheds are merged together using information of neighboring watersheds instead of the D8 cells. This progressive merging process starts from small neighboring watershed to larger ones. The example and applications demonstrated that the proposed watershed‐merging algorithm is effective in resolving the DAFA problems and identifying channel networks.