基于ASTER的喀斯特流域地表水系自动提取研究——以贵州省为例

根据喀斯特流域孤峰和峰林在ASTER影像上表现为色调深浅不一的“桔皮状”和“花生壳状”图形,河流和湖泊色调较深,湿地和干谷色调相对较浅等影像特征,对贵州省内32个典型的喀斯特流域进行数字高程和地表水系提取。结果表明,利用ASTER影像提取喀斯特地表水系简便快捷、准确率高。与从1: 25万水文地质图提取的水系进行对比, ASTER所提取的水系其流域面积最大的相对误差为4. 5892% ,主河道长度最大的相对误差为3. 5693% ,河网密度最大的相对误差也只有7. 2564% ; 从地图提取的水系最多只能达到二级支流,提取的河流相对较短,而从DEM 提取的水系可达三级,有些甚至达四级、五级以上,且提取的河流更长,提取的水系更完整。 

ASTER supported research on automatic extraction of karst surface water-A case in Guizhou province

DEM and surface river system of 32 typical karst basins are extracted according to the ASTER image showed by the isolated peak and peak forest as well as other landforms in karst basin.The ASTER image assume to different features as following,the isolated peak and peak forest assume to tones and pattern of orange skin and peanut hull,the hue of river and lake are deeper and wet land and dry grain relatively lighter.The results show that to extract surface river system by means of ASTER is simple and fast and accurate.Contrasting to extract river system by hydrogeological map of 1:250 000 scale,maximal proportional error of drainage area extracting by ASTER is 4.589%,maximal proportional error of the main river length 3.569 3%,and river network density 7.256 4%.To extract river system by hydrogeologic map,it can only reach the 2nd grade branch and the river length relatively shorter;but can reach 3rd even 4th or 5th grade branch and the river length is much longer by DEM.