黄土丘陵沟壑区1∶1万及1∶5万比例尺DEM地形信息容量对比

黄土丘陵沟壑区地形变化异常复杂 ,1∶5万地形图对原始 1∶1万地形图等高线形态综合、取舍程度很大 ,这些都在不同程度上影响了地形分析结果的准确性。以高精度的 1∶1万比例尺DEM为校准值 ,运用 1∶1万及 1∶5万比例尺DEM叠合比较分析的方法 ,研究 1∶5万DEM的地形信息容量及提取不同地形要素的精度。试验结果表明 ,在黄土丘陵区 ,与 1∶1万DEM相比 ,1∶5万DEM在所提取的地面坡度、地面曲率、沟壑量等地形定量指标方面均都存在着较大的误差。

Taking Jiuyuan valley in the loess hill and gully area as a test site, the accuracy of terrain variables derived from 1∶50 000 scaled DEMs by means of a careful comparison with high accuracy DEMs of 1∶10 000 scaled is probed into. The experiment shows a big error between the terrain variables(i.e. slope gradient, surface curvature, channel networks etc.) derived from the both information sources. At present, 1∶50 000 scaled DEM has been set up in the whole country, which will be applied as an important bas...