祁连山东段庄浪河流域地貌特征及其构造指示意义

晚新生代以来,青藏高原北东向扩展,致使祁连山地区遭受了强烈的构造隆升,造就了祁连山地区复杂的构造格局和急剧变化的构造地貌,其典型水系流域地貌特征揭示了该地区的新构造活动和地貌演化过程。庄浪河流域位于祁连山东段,作为青藏高原北东向扩展的前缘地区,庄浪河流域的地貌参数对构造活动非常敏感,提取庄浪河流域的地貌信息,有助于揭示祁连山东段庄浪河流域地貌对构造活动的响应,及系统探讨该区地貌发育特征及其所蕴含的构造意义。庄浪河流域内及边缘发育有庄浪河断裂、天祝盆地南缘断裂、疙瘩沟隐伏断裂以及金强河-毛毛山-老虎山断裂。晚新生代以来,这些断裂仍在活动,并且控制着流域内的构造变形、山体隆升和河流水系地貌发育。本研究采用ALOS DEM 12.5 m数据,基于ArcGIS空间分析技术,通过高程条带剖面、河流坡降指标体系（K,SL,SL/K）和Hack剖面、面积-高程积分值（HI）和积分曲线（HC）等方法,对庄浪河流域地貌特征进行了初步分析。结果表明,庄浪河地区地形起伏由北西向南东递减,构造活动存在东西分异的规律;庄浪河流域内部K值、SL、SL/K、HI值西侧高于东侧,Hack剖面西侧相比东侧上凸更明显;H...

Geomorphic feature of the Zhuanglang River Basin in the eastern margin of Qilian Mountains and its tectonic implications

Since the late Cenozoic, the northeast extension of the Tibetan Plateau has resulted in a strong tectonic uplift in the Qilian Mountains, which formed a complex tectonic pattern and a rapidly changing tectonic landform in the Qilian Mountains. The geomorphological features of the typical river basins reveal the neotectonic activity and geomorphological evolution in the region. The Zhuanglang River basin is located in the eastern segment of Qilian Mountains. As the front area of the northeast expansion of the Tibetan Plateau, the geomorphic parameters of the Zhuanglang River basin are very sensitive to tectonic activities. Extraction of geomorphic information in the Zhuanglang River Basin is helpful to reveal the response of geomorphic to tectonic activity, and to systematically discuss the geomorphic development characteristics and its tectonic significance in the area. There are Zhuanglang River fault, south Tianzhu Basin fault, Gedagou concealed fault and Jinqiang river-Maomaoshan-Laohushan fault in the basin and its margins. Since the late Cenozoic, these faults have been active and control the tectonic deformation, mountain uplift and river drainage geomorphology development in the basin. Based on ALOS DEM 12.5-m data and ArcGIS spatial analysis tool, this study conducted a preliminary analysis on the geomorphic characteristics of Zhuanglang River basin through elevation strip section, river slope index system (K, SL, SL/K) and Hack section, area-elevation integral value (HI) and integral curve (HC). The results show that the topographic relief in the Zhuanglang River area decreases from NW to SE, and the tectonic activity has the rule of east-west differentiation. The K, SL, SL/K and HI values in the west are higher than those in the east, and the up convexity in the west of Hack profile is more obvious than that in the east. The west side of HC curve is mostly convex or S-shaped, and the mutation of SL is mainly controlled by fault tectonic activities. The uplift rate of the west side of the basin is higher than the erosion rate, and the geomorphic evolution is in the early or mature stage. The Zhuanglang River fault still has tectonic activity since the late Cenozoic, and the drainage pattern of the Zhuanglang River area is controlled by reverse wash slip.