基于不同分辨率DEM的南江县坡度提取分析

坡度是影响土壤侵蚀的一个重要因子。该文以ASTER GDEM_30m为基础数据,结合全国1∶400万矢量数据,进行重采样获取分辨率为40m、50m、60m、70m、80m的DEM数据,通过坡度提取与重分类获取数据来对比不同分辨率下南江县坡度的变化趋势。结果显示:南江县北部坡度大,南部坡度小,与其北高南低的地势相吻合,坡度主要集中在8~35°;分辨率越低,对地形的概括程度越高,坡度不断变缓,向中等分级集中;南江县超过30%的坡度高于临界坡度,加之其复杂的地质环境,土壤结构疏松,水土流失严重。基于DEM对南江县坡度进行提取对比分析,以期为该区水土流失的研究提供有效的依据。

Slope-extraction Analysis of Nanjiang County from Different Resolution DEM

Slope is one of the key factors for soil erosion.Based on ASTER GDEM_30m data with high spatial resolu?tion and 1∶4 million vector data of national,the different resolution DEM of 40m,50m,60m,70m,80m were extract?ed with the tool of resampling,then extract slope and reclassify to show the trends of Nanjiang's slopes under differ?ent resolution DEM.The results show that,the north of Nanjiang County are steep slopes,and the south of Nanjiang County are small slopes,this is consistent with the terrain of Nanjiang County. These slopes mainly concentrate in a scope between 8° and 35°,the lower resolution DEM,the higher summarize of terrain,and the slower of slope,then the slopes tend to the classify of moderate.More than 30%of Nanjiang's slopes are higher than critical slope,in addi?tion,the complex geological environment and loose soil structure,the loss of water and soil is serious. The study of the slope-extraction analysis of Nanjiang County from different resolution DEM is looking forward to provide basis for research of water and soil conservation.