【摘要】 "5·12"汶川地震震后3年多以来,串珠状堰塞湖群的形成和发展,对震区河流演化的影响重大。通过对汶川地震灾区岷江支流——渔子溪的耿达—映秀河段的野外考察发现,堰塞坝对河流挤压造成异岸冲刷,河道横向展宽或弯曲;多堰塞湖河段河床抬升强烈;部分堰塞坝由于未完全溃决而逐渐发育成尼克点,从而形成阶梯状河床。鉴于野外考察的局限性,通过野外水槽实验初步探索了堰塞湖级联溃决的动力学特征,堰塞湖级联溃决放大了山区河流洪水的峰值流量,从而加剧了河流沿程冲淤程度,更有利于梯级河床的形成。探索多堰塞湖河段堰塞湖级联溃决情况下的河床演化规律,旨在为地震灾区河道修复及灾后恢复重建提供科学指导。更多还原

【Abstract】 A field investigation of Gengda-Yingxiu reach of Yuzixi River,a tributary of the Minjiang River,found that the river was always either squeezed by natural dams,resulting in river bending or broadening laterally,or the river was uplift strongly,or developed into step-like riverbed.Considering the limitations of field investigation,the dynamic characteristics of peak discharge of dammed lakes cascade failure were explored by field flume experiments.The amplified scale of peak discharge intensified the degree of erosion and deposition along the flume,which could be conducive to forming the step-like riverbed.更多还原