数字高程模型地形描述精度量化模拟研究

在首先提出数字高程模型（DEM）地形描述误差（Et)概念的基础上，以我国5个不同地貌类型区为试验样区，采用比较分析的方法，研究EDEM地形描述误差的成因、影响因素、量测方法以及误差的数学模拟途径。统计分析的结果证明DEM地形描述误差与DEM空间分辨率及其地面粗糙度之间存在着线性相关关系，回归分析结果显示，DEM地形描述误差Et的均方差RMS值可以表达为DEM水平分辨率（R）与地面垂直曲率（V）的函数：RMS Et=(0.0063V 0.0066)R-0.022V 0.2415。该结果可用以估算估算所建立的DEM的地形描述精度，也为确定适宜的DEM分辨率提供了理论依据。

A Simulation on the Accuracy of DEM Terrain Representation

This research puts forward the concept of DEM terrain representation error (Et) first and then investigates the generation, major factors,measurement and simulation of Et. A multi resolution and multi relief comparative approach was used as the major methodology in this study. The experiment reveals a quantitative relationship between the errors and the variation of DEM resolution and terrain roughness at global levels. RMS Et is regressed against the mean profile curvature ( V ) and DEM resolution ( X ) at 6 resolution levels. It is found that the RMS Et may be expressed as RMS Et=(0.006 3 V+0.006 6)R-0.022 V +0.241 5. This founding should be helpful in calculating DEM accuracy, as well as determining the DEM resolution appropriate to the accuracy requirement of a particular application.