基于汇水度的平坦地区水系提取算法研究

Research of Drainage Network Extraction Algorithm on Pruning Condition of the Cohesion-degree on Flat Area

本文在已有剪枝算法的基础上进行改进,以"不同地形汇聚水的能力不同"为突破点,定义"汇水度",反映此点上游地形特征,表征此种地形汇聚水的能力;再以"汇水度"作为剪枝条件,进行水系剪枝。选取汇水能力相对较弱的平坦地区进行对比实验,结果表明:应用这种以"汇水度"作为判定条件的剪枝算法,识别河源的准确性有所提高,提取水系的整体形态、河源数、总河长、主河长及支流河长等水系参数与实际水系的对应参数也更加接近。

The existing pruning algorithm was improved, and the catchment ability of water in different terrains is known as the breakthrough point of studying. ＂Cohesion - degree＂ is defined, and it reflects the topography of the upstream and the water catehment ability in the terrain. As a pruning condition of ＂cohesion - degree＂, the branches of water are pruned. On the flat area, the contrast experiments are conducted, and the results shows that： the recognition accuracy of the sources of river is improved, because of ＂the cohesion - degree＂ being regarded as a condition of the pruning algorithm. The parameters of the extracted river, such as the whole river, the number of the sources of river, the length of the whole river, the length of the main river, the length of the branches of the river, are more closed to the parameters of the aetual river.