DEM插值误差的分布及与地形因子的相关性研究——以黄土高原丘陵沟壑区的试验为例

An investigation of the distribution of DEM interpolation error and the relevance with terrain factors——The experiment of hilly and gully region of loess plateau is taken as an example

本研究采用ASTER-GDEM V2版的DEM高程数据,以黄土高原丘陵沟壑地貌区为试验区,运用交叉验证和相关性分析对插值误差的分布特性、高程误差与坡度、曲率误差的相关性进行研究。研究结果表明:高程误差的频率分布和空间自相关性程度与原始数据的密度和插值方法有关,当原始数据密度较低时,DEM误差表现出较强的空间自相关,频率分布也接近于高斯分布,随着数据密度增大,DEM误差的空间自相关性随之减弱,DEM误差分布呈现出更为明显的尖峰分布。从DEM全局来看,DEM误差与坡度比曲率有更强的相关性,且相关性随着数据密度减小呈现减弱趋势。

In this study,the DEM elevation data of ASTER GDEM V2 was used to study the distribution characteristics of interpolation error and the relevance of elevation error and terrain factors by using cross-validation and correlation analysis.The result shows that the distribution of elevation error and the degree of spatial autocorrelation are related to interpolation method and the density of original data.The DEM error shows strong spatial autocorrelation,and the distribution is closed to Gaussian when the density is low.As the density increases,the spatial autocorrelation of DEM error decreases,and the distribution of DEM errors shows a much more leptokurtic distribution.At the level of whole DEM,the DEM error shows much stronger relevance with slope gradient than curvature,in which the relevance decreases when the density of original data goes down.