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| n this paper we took Yan’er Gully watershed for an analysis instance, using ArcGIS software as a digital terrain analysis tool for studying topographic attributes extraction and analysis methods based on grid DEMs. The spatial and statistical distribution of topographic attributes were computed and compared. We assumed that a relative real DEM which is consistent with natural land surface can be produced through reconditioning basic material generated DEM and reprocessing DEM. We used mathematic statistics method and comparative analysis method to analyze effect of DEMs with different resolutions on the outcome of topographic terrain extraction, including elevation, slope, topographic index (i.e. ln (α/tan β)), watershed and subwatershed area, and drainage network. The analysis results of effect of DEM with different resolution on topographic attributes derived form DEMs indicated that terrain is smoothed, the mean value of slope decreases, the mean value of ln(α/tanβ) distribution i |
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| Keywords:DEM; Topographic attribution; DEM resolution; drainage network; |
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