三维激光扫描提取DEM的地形及流域特征研究

以三维激光扫描系统为工具,建立黄土高原丘陵沟壑区绥德县桥沟小流域高精度DEM.在ArcGIS中将高精度DEM和该流域1:1万DEM分别牛成6种栅格大小不同的DEM图像.用2种精度、6种不同水平分辨率的DEM提取研究区的地形及流域特征,进行对比分析.结果表明:与1:1万DEM相比,高精度DEM提取出的研究区流域面积变小,平均坡度、平均高度、沟壑密度增大,河网密度、河道坡度增大,能够更加详细、准确地描述研究区的地形及流域特征,对流域水文过程分析以及水土保持研究起剑积极作用.

Landform and Hydrological Character Extraction Based on High-precision DEM

Based on 3D laser scanner system, the paper takes the Qiaogou small basin locating in hilly and gully region, Suide County as test region, sets up its high-precision DEM. Three kinds of DEM raster images of different sizes(six together) in the basin were gotten by high-precision DEM and 1:10 000 DEM in ArcGIS respectively. With two kinds of precision, six kinds of different levels of precision of the study area DEM extracting and contrasting character of the terrain and drainage basin. The results show that:contrasting with 1:10 000 DEM, high-precision DEM of the study area can extract smaller drainage area, larger average slope, higher average height and density and gully, augmenting river network density and river gradient and so on. Consequently, it can describe more detailed and accurate to character of the terrain and drainage basin, and plays a positive role in analyzing process of hydrology and researching soil and water conservation.