ISSN 1000-3665 CN 11-2202/P

    四川省泸定县Ms6.8级地震地质灾害发育规律与减灾对策

    Characteristics of geological hazards and it’s mitigations of the Ms6.8 earthquake in Luding County, Sichuan Province

    • 摘要: 2022年9月5日四川省泸定县发生Ms6.8级地震,诱发大量次生地质灾害。为深入认识此次地震地质灾害发育分布规律及特征,分析地质灾害发展趋势及潜在风险,文章基于现场调查获取的一手资料,结合震区首轮地质灾害排查成果、遥感解译和区域地质背景综合研究,对地震地质灾害的特征、控灾条件及防灾减灾对策进行了研究。结果表明:截至2022年9月14日22时,地震重灾区泸定县和石棉县境内,地震共诱发有威胁对象的地质灾害隐患点565处(包括崩塌331处、滑坡234处),导致81处已有地质灾害隐患点加剧变形;地震诱发的地质灾害类型主要以中、小型群发性高位崩塌和滑坡为主,主要集中分布在震中附近地震烈度Ⅸ度区域,包括泸定县磨西镇、得妥乡、得妥乡—德威镇段大渡河两岸及石棉县草科乡、王岗坪乡;根据汶川地震经验,认为位于地震烈度Ⅸ度区内的湾东河等流域,在未来5 a内泥石流将处于活跃期,泥石流防治工程设计需考虑其高频率、黏性泥石流等特征;得妥乡—德威镇段大渡河两岸残留在坡面的崩滑体在降雨作用下易转化成坡面泥石流,建议在防治工程设计时要充分考虑2种灾害类型的转化形式。研究可为震区地震地质灾害防范及灾后重建规划提供科学参考。

       

      Abstract: On September 5th, 2022, the Ms 6.8 earthquake in Luding County, Sichuan Province induced large numbers of geological hazards. In order to deeply understand the evolution, distribution, and characteristics of geological hazards caused by the earthquake, we obtained the distribution of geological hazards by the field investigation and remote sensing interpretation. The conditions for hazard control and the countermeasures for hazard prevention and reduction are also analyzed. The results show that as of 22:00 on September 14, 2022, the earthquake has induced 565 geological hazards with threat objects in Luding County and Shimian County (including 331 collapses and 234 landslides), and 81 existing geological hazards whose deformation increased. The geological hazards induced by the earthquake are mainly medium and small mass high-level collapses, which are mainly concentrated in the areas with Seismic intensity zone of Ⅸ near the epicenter. These areas include Moxi Town, Detuo Township, both banks of Dadu River between Detuo Township and Dewei town in Luding County, Caoke Township and Wanggangping Township in Shimian County. According to the experience of the Wenchuan earthquake, the debris flow will be active in the next five years, and its characteristics of high frequency and viscous debris flow should be considered in the design of debris flow prevention and control engineering. Under the rainfall condition, the landslide deposition remaining on the slopes of Dadu River banks in the section of Detuo Township—Dewei Town can easily transform into debris flow. The transformation forms of the two hazards’ types should be fully considered in the design of prevention and control projects. The study can provide a reference for earthquake geological hazard prevention and post hazard reconstruction planning in the earthquake area.

       

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