基于不同精度DEM的黄土丘陵沟壑区地形指标提取误差分析

Error Analysis of Terrain Indexes in Loess Hilly Region Based on DEM

在宁夏盐池县南部黄土丘陵沟壑区以1∶5万和1∶10万地形图制作的DEM为研究对象,以ARC/INFO地理信息系统软件为基本技术平台,分别提取了地面坡度及坡向、平面曲率、剖面曲率4个地形指标,并进行了对比分析。结果表明,2种精度DEM在黄土丘陵沟壑区地形指标的提取上均存在不同程度的误差。最后提出了运用负地形法从DEM提取平面曲率的方法。

Based on DEMs made from the topographic maps of 1：50 000 and 1：100 000 map scaled of loess hilly region in Yanchi county of Ningxia, the terrain slope and aspect, plane curvature, profile curvature were derived and analyzed. The result showed that different errors could be found in 4 indexes. A kind of method to derived plane curvature from DEM was put forward by negative terrain method. The result could be used to guide the error-rectifying and the accuracy-evaluation of the DEMs in practical applications.