ISSN 1000-3665 CN 11-2202/P

    拒马河上游极端降雨引发地质灾害特征与链生演化过程

    Characteristics and chain-generated processes of extreme rainfall-induced geohazards in the upper reaches of the Juma River

    • 摘要: 2023年7月29日至8月1日,华北地区发生了历史上罕见的极端降雨事件,在京冀西部山区引发了大量突发性地质灾害,造成严重的人员伤亡与财产损失。在总结分析京冀西部山区“23•7”极端降雨引发地质灾害特征的基础上,采用现场调查、无人机航拍和数值模拟方法,分析了拒马河上游地质灾害发育特征,以西塔村地质灾害链为例,模拟分析了地质灾害链的形成演化过程。结果表明:(1)京冀西部山区“23•7”极端降雨引发的地质灾害表现出明显的群发性和链生性,浅表层崩塌、滑坡数量多,常成为泥石流的物源,共同构成崩塌滑坡-泥石流-堵河-溃决灾害链;(2)拒马河上游地质灾害链表现出长链条演进、多物源加积的特征,单条灾害链长度可达1.2~1.5 km,浅表崩滑物源可在灾害链的形成区和流通区同时补给,呈现灾害链规模放大效应;(3)数值模拟结果显示,西塔村后山两条沟域灾害链单独启动工况下的最大堆积厚度分别为7.1 m和6.2 m、同时启动工况下的最大堆积厚度达8.6 m,灾害链最大运动速率达9.1 m/s,表现出典型的单灾链多物源加积放大和多灾链汇聚放大特征,成为京冀西部山区极端降雨引发地质灾害链的新特点。研究相关认识对于北方山区地质灾害链风险防范具有一定指导意义。

       

      Abstract: From July 29 to August 2, 2023, a historically rare extreme rainfall event occurred in North China, which triggered a large number of geohazards in the mountainous areas of western Beijing and Hebei, resulting in serious casualties and property losses. This study analyzed the characteristics of geohazards under the extreme rainfall of “23•7” in Beijing-Hebei region, using on-site investigation, UAV aerial photography, and numerical simulation methods. The analysis focused on the geohazard characteristics in the upper reaches of the Juma River, examining the formation and evolution process and movement characteristics of the geohazards chain in Xita village. The results show that the sudden geohazards in the Beijing-Hebei region exhibited a clustered pattern, with frequent shallow surface collapses and landslides, which often became the source of mudslides, forming of a complete disaster chain of shallow surface landslide-mudslide-river blockage-failure together. The geological disaster chain in the upper reaches of the river shows the characteristics of long chain evolution and multiple sources of material accumulation. The length of a single disaster chain can reach 1.2~1.5 km, with the sources of shallow avalanches and slides replenishing both in the formation area and circulation area of the disaster chain, amplifying the scale of the disaster. Numerical simulation results show that the movement speed of the geohazards chain in Xita Village reaches up to 9.1 m/s. The maximum accumulation thickness in the two ditches was 7.1 m and 6.2 m when activated individually, and 8.6 m in the case of simultaneous activation, with the movement process showing typical multi-source accretion and amplification. This study provides valuable insights for risk prevention and management of sudden geohazard chains under extreme rainfall in northern mountainous areas.

       

    /

    返回文章
    返回