基于滤波方法的DEM尺度变换方法研究

Genaralizing the Fine Resolution DEMs with Filtering Method

针对水土流失评价中地形因子的尺度效应问题,引入数字图像处理中的滤波分析方法,对5 m分辨率DEM进行了滤波处理,并通过地形综合特征分析,坡度、曲率制图统计分析,派生等高线与河流提取统计分析等方法,对滤波处理的综合效果进行了分析论证。结果表明,利用滤波方法可以实现对高分辨率DEM的综合,利用比例尺因子为5或者10的处理,其结果与10 m分辨率DEM或1∶5万地形图在反映地形起伏方面相似。

Oriented to examine the impacts of scales of topographic parameters in regional soil erosion assessment, filtering method was applied to generalize fine resolution DEM （cellsize ： 5 m） in ERDAS and Arc-GIS systems. The effects of generalization have been assessed by comparing the general topographic characters, statistical analyzing of derived slopes and curvatures, as well as resultant contours and streams. The results show that fine resolution DEMs can be generalized, and the generalized DEMs, with a scaling factor of 5 or 10, and a 3 ＊ 3 filtering window, are comparable to 10 m resolution DEMs and 1 ： 50 000 topographic maps in representing ground reliefs.