基于数字高程模型(DEM)的可可西里地貌及区划研究

基于数字高程模型(DEM)数据,应用地理信息系统(GIS)方法,对可可西里地区地貌要素进行定量分析,并对其地貌区划进行研究。可可西里地区海拔分为中海拔、高海拔和极高海拔三级,其中高海拔地区占据69.38%的区域。研究区夷平面广泛发育,根据地势起伏度可划分为丘陵、平原和台地3种类型。除东部三江源地区外,研究区主体未受到青藏高原强烈隆升造成的河流溯源侵蚀影响,坡度类型以小于15的微斜坡、缓斜坡和斜坡为主,地势平坦。依据地貌形态特征定量分析、地貌类型组合和地貌成因的差异性原则,可可西里地区可划分为4个地貌区:羌塘高原地貌区(Ⅰ)、东昆仑山山地地貌区(Ⅱ)、三江源丘状山原地貌区(Ⅲ)和柴达木高原盆地区(Ⅳ)。其中,羌塘高原地貌区又可划分为可可西里高原地貌亚区(Ⅰ_1)和唐古拉山高山地貌亚区(Ⅰ_2),东昆仑山地地貌区可划分东昆仑南部极高山地貌亚区(Ⅱ_1)和东昆仑北部高山地貌亚区(Ⅱ_2)。地貌要素研究可以直观、量化地反映可可西里地区海拔、地势起伏度及坡度特征,地貌区划研究可以反映可可西里地区高原、山地、山原、盆地的地貌格局和水平分异,对研究地貌特征、地貌类型及开发保护具有重要意义。

Research on Geomorphological Morphology and Regionalization of Hoh Xil Based on Digital Elevation Model (DEM)

The geomorphological morphology was analyzed quantificationally and the geomorphological regionalization was studied detailedly based on Digital Elevation Model (DEM) of Hoh Xil area combinated with platform of Geographic Information System (GIS). Research suggests that the Hoh Xil area composes of three types in terms of absolute altitude: the middle, the high and the highest, and the high altitude type makes up about 69.38%. Due to the formation of planation surface, the relief amplitude in this area is less than 200 m mainly included plain, tableland and hill. Rivers headward erosion caused by strong uplift of Qinghai-Tibet plateau was not exert an influence on the Hoh Xil except Sanjiangyuan region. So the primary compose of slope type are micro slope, slow slope and slope which all less than 15°. According to regional differentiation of the essential geomorphological types and their genesis, the Hoh Xil is divided into four major geomorphological regions: the Qiangtang plateau (Region Ⅰ), the east Kunlun mountains (Region Ⅱ), Sanjiangyuan hill mountains (Region Ⅲ) and Qaidam plateau and basins (Region Ⅳ). Moreover, the Region Ⅰis divided into Hoh Xil plateau lake basin (SubregionⅠ1) and Dangla high mountains (SubregionⅠ2). The Region Ⅱ is divided into southern highest mountain (Subregion Ⅱ1) and northern high mountains (Subregion Ⅱ2). The morphology research which reflect altitude, relief and slope and regionalization research which show geomorphological pattern and horizontal differentiation of plateau, mountain land, mountain plateau and basin will be of great significance in geomorphic, landform type and exploitation, protection in Hoh Xil.