内插方法对黄土丘陵DEM精度的影响

Accuracy impact on interpolation method in loess hilly region

内插方法是影响数字高程模型精度的主要因素。以黄土丘陵样区为例,采用检查点、等高线套合等方法对内插结果进行精度分析,并在此基础上分别提取坡度、坡向等地形因子进一步评价各内插方法的优劣。实验结果表明:1)利用检查点法、等高线套合法进行精度分析的最优插值方法为径向基函数算法,样条函数插值次之;2)利用地形因子进行的精度对比分析结果显示样条函数插值方法最优,径向基函数算法次之;3)两种方法一致表明在实验区自然邻域插值、反距离加权插值(IDW)、Kriging插值的插值效果相对较差。

Interpolation is the main factor that affects the precision of DEM.Choosing suitable interpolation methods for different regions can effectively improve the precision of DEM.Taking the Jiuyuangou loess hilly area as an example,the accuracy of interpolation results is analyzed by means of check point and contour line nesting.On the basis of this,the terrain factors such as slope and aspect are extracted to further analyze the accuracy.The result shows that:a)The optimal interpolation method using the checkpoint method and the contour set method for precision analysis is the radial basis function algorithm,followed by spline function interpolation;b)The results of the precision contrast analysis using topographic factors show that the spline interpolation method is the best,and the radial basis function algorithm is second;c)The method consistently shows that the interpolation results of natural neighborhood interpolation,inverse distance weighted interpolation(IDW)and Kriging interpolation in loess plateau are relatively poor.