等高线生成规则格网DEM适宜分辨率的选取方法研究

等高线数据是生产规则格网DEM的常见数据,生产过程中DEM适宜分辨率的选取直接决定DEM的地形表达精度,影响下一步数字地形分析的结果。本文以辽宁某丘陵样区1∶50 000地形图中等高线为基础数据,首先,基于整体地形特征及等高距对适宜分辨率做出大致判断,通过初步分析确定6种备选分辨率;然后,基于不同分辨率坡度均方根误差(Slope RMSE)在格网大小逐渐减小的过程中趋于稳定的特性确定适宜分辨率;最后,利用重构等高线与原始等高线的对比结果验证适宜分辨率选择的准确性。经过实验得到样区数据适宜分辨率为20 m。

Study on the Method of Choosing the Appropriate Resolution for Generating Regular Grid DEM from Contour

Contour is a common data of generating regular grid DEM. The selection of appropriate resolution of DEM in this process di-rectly determines the accuracy of terrain expression of DEM and directly affects the result of the next digital terrain analysis. In this pa-per, based on the contour line of 1:50000 topographic map in a hilly area of Liaoning Province. First, make a general judgment on the appropriate resolution based on the overall topographic features and contour height. Through the preliminary analysis to determine the six kinds of alternative resolution. Then, based on the characteristics that the Slope Root-mean-square error ( Slope RMSE) of different resolution is stable when the size of the grid is gradually reduced, the appropriate resolution is determined. Finally, the accu-racy of appropriate resolution selection is verified by comparing the reconstructed contour with the original contour. After the experi-ment, the suitable resolution of the sample data is 20 m.