川西水洛河流域构造地貌研究

Tectonic Geomorphological Studies on Shuiluo River Basin in Western Sichuan

选择青藏高原东缘水洛河流域,对青藏高原东缘新生代期间构造隆升的响应过程及特征进行研究。利用数字高程模型,提取分析了水洛河的河流纵剖面形态、凹度指数和陡峭指数(k_(sn))等构造地貌指标。研究发现水洛河流域内存在着两期裂点,裂点将河流划分为了三个河段,每个河段的河道参数存在着较大差异;流域内部陡峭指数存在着由北向南逐渐增大的趋势。排除一系列非构造因素的影响后,最终确定了构造对研究区陡峭指数空间分布的主控作用。流域南部区域受木里断裂的影响,隆升速率较高,并在出水口处形成裂点向上游传递。此外水洛河流域广泛存在的两期裂点,也反映了在青藏高原东缘至少经历了两期构造抬升。

Studies were carried out for the response process and features of tectonic uplifting during the Cenozoic era of eastern edge of the Qinghai-Tibet Plateau and Shuiluo river in eastern edge of the Qinghai-Tibet Plateau;the digital elevation model was used to extracted and analyzed the longitudinal profile morphology,concavity index,steep index and the other tectonic geomorphological indicators of Shuiluo river.Two-stage rupture point was found in Shuiluo river basin,the rift divide the river into three river reach,the river course parameters of each river reach has larger differences;the steep index inside the river basin has the tendency that it gradually increases from south to north.A series non-tectonic factors’influence were excluded,it is finally confirmed the master control role of tectonics for study of steep index spatial distribution.The southern region of river basin affects by Muli breaks,the uplift rate is high,and a rift point formation on water outlet and pass upstream.Moreover,two-stage rift widely exists in Shuiluo river basin,it also reflects that the eastern edge of the Qinghai-Tibet Plateau has undergone two phases of tectonic uplift at least.