北京市门头沟区“23·7”强降雨引发地质灾害特征及防治建议

Characteristics and prevention suggestions of geological disasters caused by "23·7" heavy rainfall in Mentougou District, Beijing

2023年7月29日20时至8月2日7时,北京出现极端强降雨天气,降水量为北京地区有仪器测量记录140年以来最高值,其中门头沟平均降水量达538.1 mm,最大降水量达1053 mm。本次强降雨引发多起地质灾害,对门头沟区生产生活造成了严重的影响。门头沟区“23·7”强降雨共引发地质灾害666处,规模以小型为主。其中崩塌592处,泥石流55处,滑坡10处,地面塌陷9处。崩塌灾害中岩质崩塌和土质崩塌大致相当,破坏类型以滑移式为主。滑坡灾害以土质滑坡为主,破坏类型均属于浅层牵引式滑坡。泥石流灾害以稀性泥石流为主,破坏类型均属于暴雨型泥石流。地面塌陷均由历史采矿引起,主要表现为塌陷坑、地裂缝等变形破裂。根据灾害现状地质环境背景及成因,综合考虑地质灾害风险等级、周边地质环境条件、工程治理可行性等,提出了“应急处置、群测群防、搬迁避让、工程治理”防治建议。

From July 29,2023 to August 2,2023,extremely heavy rainfall occurred in Beijing,with the highest precipitation recorded by instruments in 140 years.The average precipitation in Mentougou reached 538.1 mm,and the maximum precipitation reached 1053 mm.This heavy rainfall has triggered multiple geological disasters,causing serious damages on production and daily life in Mentougou District.A total of 666 geological disasters(mainly small-scale)took place including 592 collapses,55 mudslides,10 landslides,and 9 ground collapses.A roughly equivalent amount of rock collapses and soil collapses happened among the landslide disasters,with sliding as the main type of damage.Landslide disasters are mainly soil landslides,and the types of damage are all shallow traction landslides.The debris flow disaster is dominated by rare debris flow,and the damage type belongs to rainstorm debris flow.Ground subsidence is caused by historical mining,mainly manifested as deformation and rupture of subsidence pits,ground fissures,etc.Based on the geological environment background and causes of the existing disaster situation,and taking into account the geological disaster risk levels,surrounding geological environmental conditions,and feasibility of engineering governance,we have proposed prevention and control suggestions such as"emergency response,group measurement and prevention,relocation avoidance,and engineering governance".