水磨沟泥石流基本特征及堵江可能性分析

The Possibility Analysis of Debris Blocking in Shuimogou Valley

水磨沟位于茂县和汶川交界处,紧邻岷江,根据现场调查,对比分析了水磨沟的震前震后的物源量,并计算了不同频率下泥石流的容重、流量、冲出量等动力学参数。采用岷江上游泥石流堵河可能性的经验判别公式对水磨沟泥石流堵江可能性进行初步分析。研究结果表明,在不同暴雨频率下,泥石流的性质为稀性-黏性,容重为1.73～2.13t/m3,规模属中-大型。通过计算和分析,水磨沟泥石流在区域性降雨条件和局地暴雨条件下,有可能严重堵塞岷江。根据水磨沟泥石流的具体情况和当地经济、社会、生态建设的需要,以及被保护对象的重要性,提出了减灾对策。

After the outbreak of Wenehuan earthquake on May 12,2008, more debris blockings have been reported. Currently, the research on identification of river blocking due to debris flow is little,and with great limitation. According to site investigation, we used the experience discrimination formula of debris blocking in upper reaches of Minjiang River, to analyze the possibility in Shuimogou Valley located there. The results showed that, in different storm frequencies, the nature of Shuimogou debris flow is from thinning to viscosity, the bulk density is from 1.73 t/m3 to 2. 13 t/m3, and the scale is from moderate to large. By calculation and analysis, no matter in regional rainfall or local storm, Shuimogou debris flow might severely block Minjiang River. According to the specific circumstances of Shuimogou debris flow, local economic, social and ecological construction and the importance of the object to be protected,we proposed the mitigation measures.