Ritter改进算法的丝绸之路经济带大区域坡度求取

Large-region slope calculation of the Silk Road Economic Belt based on improved Ritter algorithm

针对地理坐标系大区域DEM数据在进行坡度求取时,常规先投影再求取坡度的方法存在着投影类型选择、重采样方法选择、分辨率大小确定及栅格对齐等所带来的操作不确定性问题,该文直接在地理坐标下进行坡度求取以减少不确定性及繁杂操作的有效方法。选取GLOBE DEM数据作为数据源,亚欧大陆作为丝绸之路经济带坡度求取研究区,将Ritter算法及地球表面距离求取公式整合得到地理坐标下坡度求取Ritter改进算法,并提出了比值系数、基准长度等概念,完成了亚欧大陆的坡度求取。地理坐标下的坡度求取方法可为大区域坡度地形因子的求取提供一种新的思路,所求取的亚欧大陆坡度数据将作为开展丝绸之路经济带有关研究的基础数据。

For the problem caused by projection,resampling,resolution and grid alignment when to calculate slope using the conventional method by projecting first in a large region,this study puts forward a useful way to reduce uncertainty and cumbersome operations by calculating slope in geographic coordinates.We selected GLOBE DEM data as the data source,and chose Eurasia as the research area of the Silk Road Economic Belt.Slope-calculating algorithm in geographic coordinates was made to calculate slope values based on integrating Ritter algorithm and the earth-surface-distance calculation formula to generate improved Ritter algorithm,and the concepts of ratio coefficient and datum length were put forward.The slope of Eurasia was calculated finally.The application value of slope calculating in geographic coordinates can provide a new method for the realization of the slope calculating in large areas,and the slope data of Eurasia can serve as the basic data for the study of the Silk Road Economic Belt.