基于ASTER-GDEM数据的羊卓雍错地区构造地貌分析

基于ASTER-GDEM数据, 运用GIS空间分析统计技术, 通过对数字地形高程、地表起伏度、地表坡度等地貌参数的统计和条带剖面及面积-高程积分等数字地貌分析, 结合前人的区域地质资料及野外实地调查和验证, 对藏南羊卓雍错地区的构造地貌特征进行了初步分析, 旨在为研究区的盆地地貌格局演化分析提供依据。研究结果表明, 研究区构造地貌总体为一近东西向盆地, 最高海拔7515 m, 最低海拔2581 m, 属于高海拔-极高海拔区域; 流域内以平原和丘陵地貌为主, 平均起伏度为314 m, 平均坡度19°, 地势起伏较小, 发育有三级层状地貌; 盆地边缘受断裂的控制, 构造现象发育, 线性影像特征明显。其东、西部分别受桑日-错那断陷带和亚东-露谷断陷带所围限, 具有多期构造活动特征。盆地南北两侧受绒布-哲古断裂和邛多江断裂控制较弱。受构造活动和地表水流综合作用的影响, 盆地内部地貌已进入老龄化阶段。 

ANALYSIS OF GEOMORPHOLOGIC CHARACTERISTICS OF THE YAMZHO YUMCO REGION BASED ON ASTER-GDEM

The DEM data, gradually advancing, is applied widespreadly in the analysis of geomorphic. In order to provide important evidences for the tectonic pattern and evolution process of geomorphy in the study area, with detailed field survey and verification as well as searching and compare with former regional geologic data, the characteristics of tectonic geomorphy have been studied, based on data of ASTER-GDEM, the utilization of GIS spatial analysis statistic technology, statistics of geomorphic parameters including the terrain elevation （including the average elevation, the maximum elevation and the minimum elevation ）, the terrain fluctuation and the surface gradient, graphic and mathematic analysis of the strip profile and the area-elevation integral. The result shows that the study area, characterized by the EW directional basin geomorphy, with highest altitude of 7515 m and lowest altitude of 2581 m, belongs to the area of high-extremely high altitude, while areas within the watershed mainly exhibits geomorphy of plain and hill. With the average fluctuation of 314 m, average gradient of 19~, the terrain fluctuates little and shows layered geomorphy of three grades. The edge of the basin is controlled by faults, where tectonic phenomena develop with obvious characteristics of linear imagines. The east and west part are controlled by the Sangri-Cuona fault belt and the Yadong-Lugu fault belt respectively, in which multi-period tectonic activities are revealed by the elevation profile. Additionally, the south and north part of the watershed basin is controlled by the Rongbu-Zhegu fault and the Qiuduojiang fault, and the faulting in north is more intensive than that in south. Influenced by the combined action of tectonic activities and surface water flow, the geomorphy has entered the aging stage of evolution.