Accuracy ssessment of DEM spatial interpolation methods

• Main Authors: Cheng Jung Tsung, 鄭榮琮
• Other Authors: Chan Shih Chien
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/88471806797897184489

碩士 === 國立彰化師範大學 === 地理學系 === 103 === Digital Elevation Model (DEM) is widely used in many applications but the capability of it, for different scale of researches, could be limited by inapt resolutions on hand. Hence, researchers usually have to interpolate available DEM to resolutions better satisfy the study scales, however, interpolation errors could also occur by it at the same time. There are many studies about the accuracy of interpolations but no optimum is declared so far, besides, more are focused on technical questions and seldom connected to geomorphologic attributes or correlations of accuracy and physiographic parameters. This paper is to compare the accuracy of 5 interpolation techniques on the whole and sub-geomorphologic areas of the study watershed, Guo-Shi watershed, middle Taiwan by statistics indices such as RMSE from the range of interpolated and original layers. The accuracy of 14 physiographic parameters generated by interpolation techniques is also examined. The study indicates spline performs better on interpolation accuracy and relief is the main factor in it. The spatial distributions of interpolation errors are similar for all interpolation techniques where errors greater than 5 meters tend to distribute on areas of ridges and river channels. On the other hand, IDW and Kriging are more stable on the accuracy of physiographic parameters.