Abstract: Strong disturbance and destruction of the earthquake zone surface was produced by the Wenchuan earthquake in 2008 which released great energy. And it caused many non-debris flow gullies change into high frequency debris flow gullies after the earthquake. For frequent occurrence of debris flow disaster at the earthquake zone in recent years, the debris flow gullies along the main highway (Du-Wen highway and provincial highway 303) in Wenchuan County were chosen as the research object. According to formation conditions and activity characteristics of debris flow after the earthquake, the key factors which influenced disaster occurrence were selected. Furthermore, considering the influence among various factors, hazard entropy model was applied to calculate the weight of every factor, and the sensitivity of debris flow in the study area was zoned. Analysis results show that the quantity of high sensitivity of debris flow gullies is as many as 47, accounting for 78.3% of the total. And these gullies are intensely distributed on the hanging wall of the center fault, especially in the valley where Yingxiu is the storm center. The proposed analysis results provide theoretical reference for debris flow prevention and mitigation in earthquake area.

Key words: geotechnical engineering, debris flow, Wenchuan earthquake, evaluation index, sensitivity, hazard entropy

摘要： 2008年汶川8.0级地震释放的巨大能量导致震区地表岩体产生了强烈的扰动和破坏，许多震前非泥石流沟转化为大规模高频泥石流沟。鉴于震区近年来频发的泥石流灾情，以汶川主要公路沿线（都汶公路和省道303）泥石流沟为研究对象，依据震后泥石流形成条件与活动特征，遴选出影响泥石流发生的关键因子，运用灾害熵理论模型，考虑因子相互之间的影响，计算各个因子的权重，对研究区泥石流进行敏感性区划。分析结果表明：较高敏感性的泥石流沟谷多达47条，占总数的78.3%，且集中分布在中央断裂的上盘，特别是以映秀为暴雨中心的峡谷地带。分析结果可作为震区泥石流防治，灾区重建的理论依据。

关键词: 岩土工程, 泥石流, 汶川地震, 评价指标, 敏感性, 灾害熵