基于ASTRE和SRTM高程数据的坡度和坡长提取与分析  

Extracting and Analyzing Slope and Slope Length Based on ASTER GDEM and SRTM Elevation Datasets

作　　者：杨勤科[1] 郭兰勤[2] 王春梅[1] 

机构地区：[1]西北大学城市与环境学院,陕西西安710069 [2]陕西测绘地理信息局,陕西西安710054

出　　处：《水土保持通报》2012年第6期142-146,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"中低分辨率坡度变换方法研究"(40971173);"流域分布式坡长研究"(41071188);水利部公益性行业专项"基于GIS的黄土丘陵区年侵蚀产沙经验模型研究"(201210081-02)

摘　　要：为了使SRTM和ASTER高程数据得到科学利用,选择东北漫岗丘陵区和黄土丘陵区,基于网络下载的SRTM和ASTER高程数据,利用数字地形分析的标准方法进行了数据处理。提取了坡度和坡长两个地形指标并与Hc-DEM(水文地貌关系正确的数字高程模型)及其提取的地形参数进行了对比,结果表明:(1)无论是高程、坡度还是坡长,均是Hc-DEM系列的数据表现最好,SRTM次之,ASTER表现较差;(2)在地形平坦地区,ASTER表面因明显的空值和洼地,使高程及其基础上提取的地形参数不具实用价值,但在地形比较陡的地区则可用;(3)基于SRTM和Hc-DEM提取的两组坡度和坡长具有相同的格局,但基于SRTM的坡度有衰减,坡长有扩展,实际应用前需进行尺度变换。In order to establish rational use of ASTER GDEM and SRTM elevation datasets,the slope and slope length have been extracted from the datasets that were downloaded from the website and have been preprocessed.Furthermore,the extracted features were compared with Hc-DEM derived variables.The results showed that：（1） the Hc-DEM derived features were much better than the SRTM and ASTER GDEM derived in terms of all the topographic variables including elevation,slope,and slope length.（2） the variables extracted from ASTER GDEM were unrealistic for the areas with gentle slope,owing to the abnormally void values and irregular sinks,but in steepy area it is useful;（3） the topographic variables extracted from SRTM and Hc-DEM showed similar patterns,while the SRTM based variables featured reduced slopes and extended slope length,suggesting down-scaling may be required if it is applied in hydrological or erosional modelling.

关 键 词：SRTM ASTER GDEM 坡度 坡长 Hc-DEM 

分 类 号：S157[农业科学—土壤学] TP79[农业科学—农业基础科学]