一弧秒分辨率DEM对侵蚀地形表达能力的分析

Analysis of the expression ability to Loess erosion terrain using 1″SRTM

针对1″SRTM数据和基于1∶50000地形图生成的DEM在黄土侵蚀区对地表形态表达能力的差异性问题,提出了一套完整的评价分析指标体系。选取陕西黄土高原6大典型黄土地貌样区,从地形属性(高程、坡度、坡向、坡长)和地形特征(山顶点、流水线、流域边界)两大方面评估了两种数据对表达黄土侵蚀区的地形表达能力。结果表明:1″SRTM对地表形态的表达能力接近1∶50000地形图所生成的DEM,但总体上还是1∶50000地形图所生成的DEM对地表形态的表达比较好,尤其是在地形比较破碎的地区。本文为1″SRTM数据在部分区域替代地形图生成的Hc-DEM,并用于与地学相关领域的研究提供了重要依据。

In order to compare the difference of topographic expression between the SRTM data product and the Hc-DEM generated by 1∶50 000 topographic maps in the loess erosion area,6 large samples are selected from south to north in Shaanxi pronvice.1" SRTM and Hc-DEM were estimated from two aspects of topographic attributes(elevation,slope,aspect and slope length)and topographic features(peak point,pipeline and watershed boundary)Variation of Data Sources in Loess Erosion Area.The results show that the ability of two DEMs to express Loess erosion terrain is closed.However,in the other hand,Hc-DEM is better than SRTM especially in the more fragmented areas.This paper provides an important basis for the study of the Hc-DEM generated by the 1″SRTM data in place of the topographic maps in some regions and used in research related to geology.