在“全域—局部”分步迭代水体信息提取方法的基础上, 通过对水体信息提取指标——水体指数的物理特性的分析实现了算法中全域阈值的自动选择与局部阈值的自适应调整, 并结合DEM 生成的山体坡度和阴影信息,减少局部迭代过程中对其他地表特征与水体信息的误判。在此基础上, 建立一种适合于高山地区冰川湖泊的自动化提取方案。试验采用Landsat 数据对喜马拉雅山地区的冰川湖泊进行信息提取, 结果表明该方法能够快速准确地完 成大区域范围内的冰川湖泊制图, 并能最大程度地消除高山地区湖泊水体识别中冰川和山体阴影的影响。

The paper develops an automatic lake delineation algorithm based on “global-local” iterative scheme. The author uses NDWI (Normalized Difference Water Index) as the water identification index for the threshold segmentation process, and the slope maps and the shaded relief maps are applied in the algorithm to differentiate the shadow features from water features. Based on these methods, an automatic lakes delineation scheme is proposed to map the glacial lakes with Landsat Imagery in Himalayas mountains area. The results show that the proposed algorithm has good performance on lake mapping over the mountain areas, and lakes can be extracted automatically, accurately and efficiently, while most of melting glaciers and hill shadow features are eliminated from the segmentation processing.