动态窗口邻域统计的高差计算方法

针对高差对于地貌类型定义、不同地貌类型范围划定以及山地灾害危险性评价的重要意义,该文将坡脚的高程定义为基准高程,提出了动态窗口邻域统计的高差计算方法。计算每个栅格到坡脚的距离,作为该栅格的对应的窗口半径;利用邻域统计的方法,搜索该窗口范围内的最低高程值,即为坡脚的高程,作为该栅格高差计算的基准高程;最终通过高程值与基准高程相减运算,获取每个栅格点对应的高差。选取四川省都江堰市虹口地区为研究区,对比两种不同的高差计算方法。结果显示:在山脊和山肩部位,动态窗口计算的高差值大于静态窗口的高差值,而位于山脚动态窗口计算的高差值小于静态窗口计算的高差值;利用动态窗口获得的高差的精度明显高于静态窗口的计算结果,其平均偏差由75.53降低为13.24。

Altitude difference calculation based on neighborhood statistics with dynamic windows

Altitude difference is widely used in the geoscience,such as the division of geomorphic types,boundary determining of different landforms,as well as hazardous assessment for slope hazards.In this paper,the base altitude was calculated by neighborhood statistics with fixed window.Neighborhood statistics with dynamic windows were applied.The distance from the pixel to the slope foot was taken as the radius of the window.Then the altitude of the slope foot was got by neighborhood statistics with dynamic windows.This dataset was taken as the base altitude for each pixel.At last,the altitude difference was calculated using the DEM data minus base altitude data.Taking Hongkou,Dujiangyan as the study area,the two methods were utilized in the region.The result showed that the proposed method significantly improved the precision,and the arithmetic average deviation decreased from 75.53 to 13.24.