江西省水文地貌关系正确的DEM建立

Creating Hydrologically Correct DEMs for Jiangxi Province

以江西省为例,基于1∶25万地形图和ANUDEM软件,探讨了省域尺度中等分辨率的水文地貌关系正确的DEM(Hc—DEM)建立方法,并对其质量进行了评价。对DEM生产过程中的数据预处理、关键参数的确定等进行了讨论,并采用等高线套合分析、随机检验点分析和水系网络分析等方法对生成的江西省Hc—DEM进行质量评价。研究结果表明,利用现有数字化地形图上的地形信息(等高线、高程点和水系),在ANUDEM软件的支持下,可建立较高质量,能正确反映地形与地表流水关系的DEM,所建立的DEM质量可达到USGS标准。建立DEM的主要参数为:分辨率50m,迭代次数30,第2糙度系数0.5。

This paper discussed the methods to create hydrologically correct DEM（Hc—DEM） at medium resolutions for Jiangxi Province using 1∶250 000 topographic maps and ANUDEM software.The quality of the DEMs was further assessed.The data preprocessing,the determination of the key parameters and others for Hc—DEM creation were addressed carefully.In addition,contour line overlay analysis,random checkpoint analysis and stream network analysis were adopted in evaluation of Hc—DEM quality.The results show that based on the topographic information of the existing digital topographic maps（including contours,spot heights,and streamlines） and the application of ANUDEM software,high-quality DEM representing the correct relationship between the stream networks and the geomorphology could be created.The quality level of constructed DEMs reached the USGS standards.The created DEM had the resolution of 50 m,iteration number of 30 and the second roughness coefficient of 0.5.