利用流域边界和坡向差自动提取山脊线

Automatic extraction of ridgelines using on drainage boundaries and aspect difference

目前山脊线的提取方法以地表曲率分析为主,其成果山脊线连续性差,实用性较难保证。其他基于流水模拟的方法也有提取成果与山脊线定义不相符等缺点。本文介绍了一种整合地表曲率分析和流水模拟2种方法各自优势来提取山脊线的方法。该方法以地表流水模拟提取的流域边界为基础,并以边界两侧地形坡向差值为地表曲率代用指标,对流域边界进行筛选来提取山脊线。本文方法具有成果山脊线连续性好、地形代表性高的特点;并能够正确提取绝大多数的地形山脊线,具有较高的几何精度。

The current ridgeline extraction methods are mostly based on surface curvature analysis, which has the shortage that the resulted ridgelines cannot connect each other ideally, therefore lead to relatively poor practicability. Other surface flow simulation methods also have some shortages such as the difference between their results and ridgeline definition. This paper presented a ridgeline extraction method which integrates the surface flow simulation and surface curvature analysis methods. The method firstly extracted drainage boundaries by surface flow simulation, and then used the aspect difference between two surfaces along the boundaries as the proxy of surface curvature, and extracted the ridgeline by removing drainage boundary lines that don＇ t have ridgeline properties. The resulted ridgelines have two distinctive characteristics including excellent connectivity between ridgeline branches, and well representations of topographic features. Furthermore, it could extract most of the topographical ridgelines with relatively higher positioning accuracy.