祁连山西段疏勒河流域地貌特征及其构造意义  

GEOMORPHIC FEATURES OF THE SHULE RIVER DRAINAGE BASIN IN QILIANSHAN AND ITS INSIGHT INTO TECTONIC IMPLICATIONS

作　　者：苏琦[1] 袁道阳[1,2] 谢虹[1,2] 邵延秀[1,2] 梁明剑[3] 

机构地区：[1]中国地震局兰州地震研究所,兰州730000 [2]兰州地球物理国家野外科学观测研究站,兰州730000 [3]四川省地震局,成都610000

出　　处：《地震地质》2016年第2期240-258,共19页Seismology and Geology

基　　金：中国地震局地震行业专项(201308012);国家自然科学基金(41030317;41302174)共同资助

摘　　要：疏勒河流域盆地位于祁连山西段,跨越了该区多条不同方向和不同性质的活动断裂带,其所呈现的地貌特征反映了该区最新构造活动的信息。文中基于GIS空间分析技术,利用SRTM-3数字高程模型（DEM）数据,系统提取了疏勒河流域及其4个亚流域盆地的面积-高程积分曲线、疏勒河水系的Hack剖面以及河流坡降指标（SL）,并对整个流域地形做了坡谱分析,获得了疏勒河流域的地貌特征。研究表明,疏勒河的流域地貌发育受到该区的阿尔金断裂、昌马断裂、托勒南山断裂以及疏勒南山断裂等强烈构造活动和区域岩性差异的影响,坡度以0°~35°的区段为主;整个流域盆地处于河流发育的＂壮年期＂;构造活动是造成河流纵剖面发生改变的最主要因素,局部河段同时还受到岩性因素的控制和影响。这表明在活跃的造山带内部,河流地貌的发育过程中,活动断裂的构造作用是重要的控制因素。Because of the strong uplift of the Qilian Shan since late Cenozoic,the drainage basins that are derived from the mountains have undergone strong tectonic deformation. So the typical geomorphology characteristics of these drainage basins may indicate the strong tectonic movement in the region. For example,the Shule River drainage basin,which originates from the western part of the Qilian Shan owns unique geomorphology characteristics which may indicate the neotectonic movement.Stream networks of the Shule drainage basin extracted from the DEM data based on GIS spatial analysis technology are graded into five levels using Strahler classification method. Four sub-catchments,numbered 1,2,3 and 4 are chosen for detailed analysis. Furthermore,the four subcatchments,the hypsometric integral curves,Hack profiles,SL index and average slope of the Shule drainage basin are determined by GIS tools. In addition,we analyzed the slope spectrum of the Shule drainage basin.The average elevation of the Shule drainage basin is very high,however,the slope of the drainage basin is very low,the gentle slope occupies so large area proportion that the slope spectrum shows a unimodal pattern and a peak value is in low slope region（ 0° ~ 5°）,so tectonic movement has a strong influence on the drainage basin. Under the intensive impact of the tectonic movement of the active fault and regional uplift,the hypsometric integral curve is sigmoid,revealing that the Shule drainage basin is in the mature stage. The Hack profile is on a convex,the longitudinal profile is best fitted by linear fitting and the abnormal data of the SL index of the Shule River has a good fit with the section through which the active fault traverses,that means the tectonic movement of the active fault has strong influence on the river＇s SL index. It is worth noting that lithologic factors also have great impact on the river geomorphology in some sections.According to the above analysis,we recognize that in the interior of active orogen,the evolution of river geo

关 键 词：疏勒河流域盆地 面积-高程积分Hack剖面 河流坡降指标 地貌 

分 类 号：P315.2[天文地球—地震学]