Digital Terrain Analysis Based On DEM Of Different Levels Resolution In Enshi

Digital elevation model (DEM) as one of the main contents of the database space, has been widely used in many fields, digital terrain analysis is performed to calculate the properties and characteristics of the terrain extracted digital information processingtechnology in the DEM, research digital terrain analysis based on DEM can provide the basis for theoretical analysis of the terrain and the means to achieve a number of areas. DEM horizontal resolution there are significant differences in the capacity and accuracy of topographic information, etc. is an important indicator to determine the topography parameters and application scales. Analysis of scale effects DEM data resolution DEM study the impact of different levels of reality has very important significance for digital terrain analysis.The southwestern Hubei Enshi as the research object, building Enshi digital elevation model, based on different terrain features horizontal resolution DEM extraction and analysis to explore the impact of different levels of resolution topographic features and hydrological characteristics, combined with topographic features and hydrological characteristics, watershed classification factor is selected, the Enshi according to different topographical features into river basin, providing basic information on digital terrain data for the Enshi, provide a reference for the integrated management of Enshi. Studies have shown that:(1) Under other conditions the same circumstances, different levels of resolution of the DEM, with decreasing levels of resolution, expressing a variety of basic topographic index is also increasingly blurred, are becoming more simplistic, began simplified, integrated terrain expression index for terrain modeling capabilities of the real terrain is gradually reduced. Slope, aspect, slope and aspect variability variability on the accuracy of the description of the terrain features are reduced gradually ignore some terrain features, reducing the real terrain simulation capabilities. (2) Different levels of resolution of the extracted river network differences exist, the more complex the higher the resolution of the extracted river network, the more close to the real Enshi river network. The same data source, with the lower horizontal resolution, the number of the extracted stream is also reduced along with the total length of the stream is reduced. Description high horizontal resolution DEM can be extracted more complex river network, and the level of the low resolution DEM extracted river network only mainstream, can not reflect the real situation river(3) The use of30m horizontal resolution DEM extraction and natural river basin segmentation results, combined with the results of other horizontal resolution under division will be divided into40Enshi basin. Select the parameters describing the more important watershed-watershed area, watershed shape roundness than as a classification factor, using hierarchical classification method, Enshi40watershed basins in turn divided into four types. Provide the basis for the integrated management of the foundation Enshi.