2017年8月8日凌晨4点至4点30分,普格县荞窝镇耿底村4组和5组发生泥石流灾害,导致25人死亡,71间房屋损毁,造成1.6亿元经济损失.采用现场调查、室内分析实验、参数模拟计算等方法对灾害的特征和成因进行了分析.研究结果显示8.8普格泥石流属于低频率中等规模的稀性泥石流.泥石流是由于流域内广泛发育的"凹槽土体"在旱后叠加暴雨的影响下激发的,其成灾过程是一系列致灾因素叠加的结果.首先,灾害与乡村道路堵塞行洪道关系密切;此外区域灾害伏旱后由局地强降雨引发,流域自然条件复杂;隐蔽性强低频率的老泥石流沟排查识别困难;流域上游无雨量观测站点,难以准确预警;洪流夜间发生,逃生难度大等因素的存在进一步促使灾害发生.%It was to investigate the genesis of a debris flow event occurred at 4 and 5 Gudong Village, Qiaowo Town, Puge County from 4 am to 4:30 am on August 8, 2017, which caused 25 deaths, 71 houses damaged and a large economic loss of 160 million yuan. The characteristics and causes of disasters were analyzed on the basis of field investigation, laboratory test and simulation. The results showed that 8.8 Puge debris flow was a low-frequency and medium-scale debris flow. It was triggered by the extensive development of hollow in the basin under the influence of superimposed rainstorm after drought, and the disaster process was a result of a series of superimposed disaster-triggering factors. First of all, the rural roads blocked the flood channel; In addition, regional natural disasters were triggered by heavy rainfalls after summer drought, which led to complex natural conditions; There was difficulty in identifying old debris flow gully with low-frequent and latent. Some factors like time, speed, difficulty of escape and so on, all of them contributed to the initiation of the disaster.
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