摘要
[目的]查明2020年5月25日云南省贡山县“5·25”强降雨诱发地质灾害的发育分布特征、形成机制及发展趋势,为该县地质灾害防灾减灾规划提供科学依据。[方法]基于灾后应急排查一手资料,在系统收集区域地质及降雨资料的基础上,对其灾害过程开展了深入分析与研究。[结果]贡山县“5·25”群发性地质灾害以滑坡和泥石流为主,规模多为小型,主要沿怒江两岸公路沿线分布,滑坡多以浅表层为主,泥石流多以土力类泥石流启动模式为主,地质灾害表现出典型的高位远程及链式灾害特征,滑坡或崩塌发生后进入沟道转化为泥石流的现象极为普遍。[结论]贡山县地质灾害调查评价中需充分考虑高位地质灾害的排查,同时科学评估地质灾害引发的链式效应及其影响区范围;由于境内植被覆盖率较高,泥石流发生后会携带大量的漂木冲出,在沟道狭窄处或沟口桥涵处易形成堵塞,对泥石流的瞬时流量会起到放大作用而翻越沟道造成灾害。泥石流防治工程设计中要充分考虑堵塞系数取值的合理性。建议对贡山县城开展大比例尺地质灾害风险调查与评价,将评价结果与国土空间规划有机融合,从源头上对地质灾害风险进行管控,同时提高县城后山已有泥石流防治工程设防等级和标准。
[Objective]The development and distribution characteristics,formation mechanism and development trend of geological hazards induced by“5·25”heavy rainfall on May 25,2020 in Gongshan County,Yunnan Province were studied,in order to provide scientific basis for geological hazards prevention and mitigation planning in this area.[Methods]Based on the first-hand data of the post-disaster emergency survey and the systematic collection of regional geological and rainfall data,the hazard process was analyzed and studied.[Results]The concurrence geological hazards in Gongshan County were mainly small landslides and debris flows,which were mainly distributed along the road and on both sides of Nujiang River.Most of the landslides were shallow surface,and debris flows were mainly initiated by landslide.The geological hazards showed typical characteristics of high-location,long-range and chain type disasters.It was very common for landslide or collapse to enter the channel and turn into debris flow.[Conclusion]In the investigation and assessment of geological hazards in Gongshan County,it is necessary to fully consider the investigation of high-location geological hazards,and scientifically evaluate the chain effect caused by geological hazards and the scope of the affected areas;due to the high vegetation coverage in the territory,debris flow will carry a large number of driftwood to rush out,which is easy to form blockage in narrow gully or at the bridge and culvert at the mouth of the gully,which will enlarge the instantaneous volume of debris flow.It is suggested to carry out large-scale geological hazard risk investigation and evaluation in Gongshan County,and organically integrate the evaluation results with the land spatial planning,so as to control the geological hazard risk from the source,and improve the protection standard of debris flow control engineering in the back mountain of the town.
作者
铁永波
阮崇飞
杨顺
曾波
张红兵
李富强
孙金峰
何振强
Tie Yongbo;Ruan Chongfei;Yang Shun;Zeng Bo;Zhang Hongbing;Li Fuqiang;Sun Jinfeng;He Zhenqiang(Chengdu Center of China Geological Survey, Chengdu, Sichuan 610081, China;Yunnan Geological Engineering Survey and Design Institute, Kunming, Yunnan 650041, China;Institute of Exploration Technology, CAGS, Chengdu, Sichuan 611734, China;Chengdu Institute of Plateau Meteorological, China Meteorology Administration, Chengdu, Sichuan 610072, China;Yunnan Institute of Geological Environment Monitoring, Kunming, Yunnan 650216, China;Gansu Geological Hazard Prevention Engineering Survey and Design Institute, Lanzhou, Gansu 730050, China)
出处
《水土保持通报》
CSCD
北大核心
2021年第2期10-15,24,共7页
Bulletin of Soil and Water Conservation
基金
国家自然科学基金项目“循环冻融作用下冰碛土的碎化效应及其对泥石流启动的影响试验研究”(41772324)
中国地质调查局项目“川西山区城镇灾害地质调查”(DD20190640)。
关键词
“5·25”暴雨
群发性地质灾害
发育分布规律
形成机制
云南省贡山县
“5·25”rainstorm
group geo-hazards
development and distribution
formation mechanism
Gongshan County of Yunnan Province
