A Research On Terrain Information Capacity Of Different Spatial Scales DEMs In Loess Plateau

Different spatial scales(scale and resolution) DEMs have great difference in the precision of terrain description. Terrain is simplified and smoothed along with the decrease of scale or reduction of resolution, and the terrain information of DEM is decreased too. The rule has been approved by research. But the capability of calculating this terrain information by quantitative method, and thus opening out the characteristic of DEM terrain description precision have great meaning in theory and value in application. Based on the summaries of former researches on topographic information and DEMs of Loess Plateau in North Shaanxi, this paper comes up with Terrain Information Capacity (TIC) of DEMs from terrain complexity and information theory, and explains the relationship between TIC and real landform. Based on 1:10 000 and 1:50 000 scaled DEMs in China's Loess plateau, derives Terrain Information Capacity. First, illustrates the spatial distributing characteristic of TIC and the decrease of TIC with lowering of scale in Loess Plateau in North Shaanxi. Second, applies grey relationship clustering to establish Change Atlas Drawing of Terrain Information Capacity of different scaled DEM. In the end, studies the relationship between TIC and other terrain factors derived from DEMs to verify the value of TIC in practice. According to the results of experiments, TIC can reflect the variety features of terrain and quantify the topographical information and explain the spatial distributing of landform, and TIC is lower as the DEM's scale is smaller. Using the Change Atlas Drawing can correct the Statistic of large scaled terrain data .The result has provided a basis for further study.