贵州省望谟县“6·6”典型泥石流灾害特征及防治建议

Characteristics of "6·6" Debris Flow Disaster in Wangmo County of Guizhou Province and Prevention Suggestions

2011年6月6日凌晨,贵州省望谟县在强降雨作用下发生大范围群发性泥石流,泥石流主要分布在降雨集中的望谟县北部山区打尖河、打易河和乐旺河上游。此次群发性泥石流是自1949年有记录以来规模最大的一次,造成了重大的人员伤亡和财产损失。对该次望谟县"6·6"泥石流的灾害特征进行了调查分析。结果表明,望谟县"6·6"泥石流主要是低频率群发性泥石流灾害。由于降雨量大,物源相对较少,泥石流以稀性为主,对沟道产生了较强的冲刷作用。泥石流危害方式主要是冲毁淤埋沟口房屋以及随之产生的灾害链效应。未来在相同降雨条件下还可能暴发较大规模泥石流灾害,建议采取避让和修建防治工程等相应措施进行防治。

A group of debris flows were triggered by heavy rainfall in Wangmo County, Guizhou Province in the early morning, June 6, 2011. The debris flows were distributed mainly in upstream catchments of Dajian River, Dayi River, and Lewang River in the north of Wangmo County. The group of debris flows was the largest occurrence since 1949, which caused numerous losses of lives and property damages. These debris flows were featured by low frequency, less viscosity debris flow, strongly erosion in the channels and large intensity of rainfall. The deposition on the fans and burial of houses were the major hazardous aftermath of these debris flows. It is very likely that these kinds of debris flows could be triggered again under the same heavy rainfall in the future. Preventive suggestions including evacuation and engineering projects were proposed to mitigate this kind of hazards.