银厂沟矿渣型泥石流特征及危险度评价

Characteristics of Slag Type Debris Flow of Yinchang Gully and Risk Assessment

泸定县银厂沟属于典型的矿渣型泥石流沟,沟域内分布大小矿场数处。尽管对大部分矿渣体做了固坡处理,但因固坡设施结构单薄,易失效,曾先后于1975、1992和2011年暴发中等规模泥石流,冲毁路基、阻塞主河道。根据银厂沟泥石流启动物源以矿石弃渣为主这一特点,选取渣堆稳定性、弃渣堆规模、汇水面积、沟道长度、沟道纵坡降、沟道弯曲度、日最大降雨量、泥石流发生频率和历史最大冲出量等9个因子,结合层次分析法对银厂沟泥石流进行危险度评价,结果表明银厂沟仍蕴藏暴发中等以上规模泥石流的风险,应尽快治理。

Yingchang gully,located in Luding County is a typical gully of slag type debris flow and there are several mines in different scales.Although the most of slag had been used for slope consolidation,the moderate scale debris flow happened in 1975,1992 and 2011 successively because of weak structure and easy failure of the slope consolidation.It washed out roadbed and blocked main channel.According to the characteristics of the start source of the gully debris flow is ore slag,the paper selected 9 factors of slag stability,slag heap scale,catchment area,length of gully,longitudinal slope,channel curvature,the maximum daily rainfall,the frequency of debris flow and the maximum amount of wash off in one event and made risk assessment on debris flow of the gully by using analytic hierarchy process.The outcomes show that the gully still has the possibility of happening debris flow greater than moderate scale.