基于DEM的青藏高原主体高原面的高程分析

Elevation Analysis of Qinghai-Xizang Plateau Surface Based on DEM Data

摘要: 作为世界上最高的高原、地球的第三极，青藏高原的形成、演化及其对世界气候变化和区域环境分异的影响，受到人们越来越多的关注。可是关于青藏高原平均海拔及高原面的分布范围还没有一个确切的令人信服的答案。本文利用SRTM3-DEM数据，运用GIS相关空间分析技术及均值变点法求取青藏高原(国内部分)高程大于3000 m区域的最佳统计分析窗口，并将该区域以100 m为间隔划分为不同的高程区间，对不同高程区间的面积，平均地势起伏度、平均地表切割度及平均坡度等地貌参数进行了统计分析。结果表明，青藏高原主体高原面的中心分布范围在4400~5300 m之间；青藏高原上，平均地势起伏度、平均地表切割度和平均坡度最小，而100 m高程间隔内地面面积最大的地方，出现在海拔4900~5000 m之间，青藏高原主体高原面的中心高程为4950 m；利用SRTM3-DEM数据，提取研究区地势起伏度的最佳统计窗口面积为1.37 km²。

Abstract: The Qinghai-Xizang plateau have been attracting more and more interest from different parts of the world, because of the particular geographic location, huge horizontal scale, vertical elevation and its great effects on the global climate change. However, up to now, there have not been an accurately calculation and systematic analysis of the elevation of the Qinghai-Xizang Plateau Surface and its distribution. Based on the SRTM3-DEM data and the technique of spatial analysis in GIS, the elevation of the Qinghai-Xizang Plateau Surface and its distribution are calculated and analyzed. It suggests that the main part of the Plateau Surface distributes in the range of 4400 - 5300 m.a.s.l and with a center elevation of4950 m.a.s.l. And it is concluded that the grid unit of 13 × 13 (1.37 km²) is the optimum statistical unit for calculating the relief amplitude in Tibet Plateau by using SRTM3-DEM.