On constructing methods of hydrologically correct DEMs
YANG Qi-Ke-;Shi-Wei-Juan-;TimR.McVicar;TomG.VanNiel;LingtaoLi
1.Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,712100,Yangling,Shaanxi,China;2.CSIRO Land and Water,GPO Box 1666,Canberra,2601,ACT,Australia
Abstract:Hydrologically correct DEMs(Hc-DEM) is one of DEMs which correctly and sufficiently represents genesis and locational relationship between hydrologic parameters,including direction and pathway of overland runoff,stream networks,and boundary of watershed,and landform,etc.As the only way to extract terrain parameters based on DEMs for the studies of watershed hydrology,and soil erosion modeling of regional scale,therefore it is necessary to constructing Hc-DEMs for representing terrain shape,extracting terrain and hydrology parameters.In this paper,the concept,constructing method of Hc-DEMs were introduced and discussed,then taking Loess Plateau as an example,key parameters for Hc-DEMs constructing based on digital topographic maps and ANUDEM software package were identified by series tests;the quality of resultant DEMs have been assessed by comparing them to DEMs from TIN approach which is widely applied in China.The results show that varied resolution Hc-DEMs can be generated based on available digital topographic maps,including features of contour,spot heights,stream lines,etc,and ANUDEM software,and provide solid support for hydrology and soil erosion modeling at the watershed/regional scales,and mapping of vegetation suitability.