云南镇雄“1·22”山体滑坡灾害调查

Field Survey of the Zhenxiong Landslide on January22, 2024 in Yunnan Province, China

2024年1月22日5时51分,云南省镇雄县凉水村发生滑坡灾害,导致凉水村合兴、和平两个村民小组共44人死亡。基于现场调查、无人机航测和遥感解译分析确定该地质灾害属中小规模滑坡,并探讨了其成因机理。结果表明:(1)镇雄滑坡是一次典型的“小滑大灾”灾害事件,其规模约11.88万m^(3),导致44人死亡;(2)滑坡发生前的坡体为一个裂缝发育的临界稳定态斜坡,岩石节理裂隙达1.4条/m,滑坡堆积石块中陈旧的历史风化断面占比超60%;(3)低温冻胀作用极可能最终触发了滑坡的发生,坡体的后端汇水、砂泥岩互层的地层和滑坡发生前的低温三个因素奠定了坡体冻胀失稳的基础。此类冬季发生的地质灾害具有极强的意外性,需引起高度重视。本研究可为高原和高纬度地区由低温冻胀作用触发的滑坡防控提供案例和借鉴。

At 5:51 a.m.on January 22,2024,a catastrophic landslide struck Liangshui village,Tangfang town,Zhenxiong county,Zhaotong city,Yunnan province,China,resulting in 44 casualties at two Sub-Village at Hexing and Heping.A emergency team was organized to examine the genesis of the landslide using on-site investigation,UAVs aerial photography and remote sensing interpretation.(1)The Zhenxiong landslide was categorized as a small-scale geo-catastrophe,with sliding mass volume about 118800 m^(3),but badly led to 44 deaths.(2)Prior to the occurrence,the original slope body developed a density of joint fractures up to 1.4/m,and weathering cross-sections were found in up to 60%of stacked rocky screes,suggesting before the slope failure there had been a critical stable state.(3)It is quite evident that the action of low-temperature frost heaving on unstable slope ultimately triggered the landslide.Three factors,the ponding/infiltrating at the rear edge of the slope shoulder,the interbedding stratum of stone-mudstone and the persistent low-temperatures ahead of the sliding laid the foundation for the catastrophe.The occurrence of such a small-scale landslide but severe consequence occurring in winter is highly unexpected,and it needs to be given high scientific concern.