农牧交错带典型样区DEM分辨率对高程梯度的影响

Effect of DEM resolution on elevation gradient in typical areas of farming-pastoral transitional zone

根据坡度算法基本项高程梯度p和q,选取陕西绥德和黑龙江拜泉两个样点,分析分辨率及组分对p和q影响。结果表明,p和q反映地形在x、y方向起伏程度。随平滑程度增加、采样间距增大及分辨率降低,p和q变化规律类似。随分辨率降低,图像平滑且产生信息损失,方差、值域变小,分布集中。分辨率及组分对p和q影响排序为:分辨率>平滑程度>采样间距。

Based on the elevation gradient(p and q),which is the basic terms of slope algorithm,Suide and Baiquan were selected,and the influence of resolution and its components,on elevation gradient was investigated.It was showed that p and q could reflect the relief of terrain in x or y directions.The change rules of elevation gradient were similar with the increase of smoothness or with the increase of sampling spacing,or with the lower resolution.The image becomes smoother,the loss of image information becomes more and more serious,the variance and the range become smaller and the distribution was centralized with the lower resolution.The order of the influence of resolution and its components on p and q was,resolution>smoothing>sampling.