四川汉源康家坡滑坡形成机理与滑坡—堰塞坝—泥石流灾害链分析

2018年8月6日中午12时,汉源县富泉镇西沟发生大规模滑坡,约1.50×10~6 m~3松散碎块石土在前期持续降雨作用下沿西沟右岸高速滑出、解体,并在主沟道内形成堰塞坝,体积约4.00×10~5 m~3。滑坡造成1人失踪,近6.70×10~3 m~2耕地被毁,紧急转移50余人。通过现场实地调查,结合无人机航飞、三维建模、地质、地震、水文、气象等资料,对康家坡滑坡基本特征进行了调查研究,调查表明,有利的地形条件、松散的覆盖层、充沛的前期降雨入渗及溪水对坡脚的冲刷是形成滑坡的主要原因。西沟原本为一条高频泥石流沟,本文在此基础上分析了堰塞坝溃坝的可能性及灾害链成灾模式。

Analysis on mechanism of Kangjiapo Landslide and consequent debris flow in Hanyuan County of Sichuan Province

At about 12∶00 pm on August 6th,2018,a large-scale landslide happened in west gully of Hanyuan County.Under the early continuous rainfall approximately 1.50×10^6 m^3 loose gravel soil at right bank slid down at high speed and disrupted,and then transferred into the barrier dam approximately 4.00×10^5 m^3.the landslide damaged about 6.70×10^3 m^2 cultivated land,causing 1 person to be died and 50 people to be evacuate urgently.Through in-situ investigation,the basic characteristics of Kangjiapo Landslide were investigated combined with Unmanned Aerial Vehicle、three-dimensional modeling,geology,earthquake,hydrology,meteorology,the results indicate that the prominent terrain condition,loose overburden,abundant early rainfall.The erosion of the slope by gullies are the main cause of the landslide.The west gully was originally a valley where debris flow frequently happened,on this basic this paper analysis the possibility of the dam-break and disaster chain disaster mode.