绵竹清平乡玉麦棚子沟泥石流风险性评价及堵江可能性分析  

Risk assessment and possibility analysis of river-blocking caused by debris flow of Yumaipengzi Valley in Qingping,Sichuan Province

作　　者：张欣[1] 王运生[1] 吴冉[2] 

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),四川成都610059 [2]安徽省地质实验研究所(国土资源部合肥矿产资源监督检测中心),安徽合肥230001

出　　处：《自然灾害学报》2017年第2期204-211,共8页Journal of Natural Disasters

基　　金：中国地质调查局地质调查项目(1212010914010)~~

摘　　要：2008年"5·12"汶川大地震以后,绵竹市清平乡在持续强降雨的作用下,引起了一系列大规模的群发泥石流。尤其是玉麦棚子沟,在震后先后爆发了3次较大规模的泥石流,对沟口处小木岭一级电站的厂房设备等造成了一定程度的损失,对电站的工作人员生命财产安全也构成了严重的威胁。在野外的实地调查及对泥石流基本特征和形成条件综合分析的基础上,进行了风险性评价和堵江的可能性分析。研究表明,玉麦棚子沟泥石流性质为粘性泥石流,整体规模中等,流域的地形、构造及物源等条件均有利于泥石流的的形成,特别是在强降雨的作用下,存在再次发生泥石流的可能性。对玉麦棚子沟进行风险性评价可知,该沟为中等风险度泥石流沟。经过计算和分析,在暴雨频率为10~100 a一遇的情况下,该沟爆发的泥石流会造成堵江事件,甚至完全堵塞主河道。A series of large-scale mass of debris flow have been caused by continuous heavy rainfall after the Wen- chuan earthquake in the Qingping township, Mianzhu City and three times larger scale of debris flow have broken out in Yumaipengzi Valley, especially. It caused a certain degree of loss for the plant and equipment of Xiaomuling Hydropower Station, life and property safety of power station staff also suffer a serious threat. Based on the field in- vestigation and comprehensive analysis of basic characteristics and formation conditions of the debris flow, the risk assessment and the possibility analysis of blocking river were carried out. The results indicate that the characteris- tics of Yumaipengzi Valley debris flow is viscous, and integral scale of the debris flow is medium; the topography, structure and material source of the basin are favorable for the formation of debris flow, especially the possibility of occurrence of debris flow again under the action of heavy rainfall; the risk assessment result of Yumaipengzi valley indicates that the valley has middle risk of occurrence of debris flow; through the calculation and analysis, in case of rainstorm of 10 - 100 years return period, the occurrence of debris flow will result in blocking the river, even completely blocking the main channel.

关 键 词：玉麦棚子沟 泥石流特征 形成条件 风险性评价 堵江分析 

分 类 号：P694[天文地球—地质学] X43[环境科学与工程—灾害防治]