在SRTM-DEM数据的基础上,运用GIS空间分析技术,系统提取了格尔木河三级流域及部分二级流域地形参数和面积-高程积分值,探讨了面积-高程积分值的面积及空间依赖性,并对面积-高程积分值(HI)对构造活动性、岩性变化、冰川作用强度的指示意义进行了研究。研究表明:HI值具有面积依赖及空间依赖性;东昆南断裂(F4)-西大滩断裂(F3)以昆仑山口为界可以分为东西两部分,各自的活动性都是中间强往两边依次减小,东昆中断裂(F1)的活动性变化不大;岩性对HI影响表现出,侵入岩的抗侵蚀力最大,片岩的抗侵蚀力最小,碳酸盐岩组合的抗侵蚀力居中;冰川作用对地貌发育和侵蚀程度有改造作用,与只有古冰川发育或无古冰川流域比较,有现代冰川发育,古冰川作用遗迹广泛的流域,HI值较大并会出现U型谷。
The interaction between tectonics and climate on landform has sparked much interest over years.The hypsometric integral(HI) value could reflect both tectonic activity and climate change,and might be a promising tool that links those two aspects.Based on SRTM-DEM data,this paper withdraws the measuring indicators of the landform and hypsometric integral from the third order basins and some of the second order basins in the Golmud river drainage basin using GIS spatial analysis,discusses the area and space dependence for hypsometric integral,and presents its significance in indicating tectonics,lithology and the degree of glacial erosion.The results show: the HI value depends on area and space;the southern fault of east Kunlun(F4)-Xidatan(F3) fault can be divided into two parts,the east and the west,by the Kunlun Pass;both of them show similar scenario that the activity decrease from the center to the sides;there is no apparent change in the activity of the central fault of east Kunlun(F1);intrusive rock shows greatest erosion-resistance while schist shows least and carbonate rocks shows modest,respectively;glacial processes could rework the landform and change the degree of erosion;the drainage basin with modern glacier and/or with extensively distributed paleo-glacier is of higher HI value and develops U-shaped valley,compared to those without or with limited paleo-glacier.