基于条件模拟的DEM误差曲面实现研究

DEM Error Surface Realization Based on Conditional Simulation

为了克服DEM全局误差指标描述DEM精度的缺陷,基于条件模拟(CS)实现了DEM误差曲面的构建。构建了甘肃省董志塬某测区DEM误差曲面,并与普通Kriging(OK)插值结果进行了比较。结果表明,OK具有明显的平滑效应,而CS能准确反映DEM误差的空间波动性。DEM误差对坡度精度的影响分析表明,相比地形复杂的区域,DEM误差严重影响平坦区域的坡度精度;对测区水土流失等级划分结果的分析表明,约有70.2%的网格点的等级划分受DEM误差的影响。

In order to overcome the limitations of RMSEs, we developed a scheme for DEM error surface construction based on conditional simulation （CS）. A DEM error surface of Dongzhi tableland locate in Gansu province were comparatively constructed based on CS and ordinary Kriging（OK）. Results indicate that OK has an obvious smooth effect, whereas CS can accurately represent the spatial fluctuation of DEM errors. DEM error has a more serious effect on slope accuracy in flat area than that in complex area; Results of water and soil loss level determination show that about 70.2 % of grids are influenced by DEM errors.