高山峡谷区滑坡-泥石流灾害链成灾模式与危险性评价——以舟曲立节为例  

Analysis of the transformation mechanism and prediction of a landslidedebris flow multi-hazards chain in an alpine canyon area:a case study in Zhouqu

作　　者：种艳 陈冠 孟兴民[2,3,4] 岳东霞 张毅[2,3,4] 郭富赟[5] 李亚军 曾润强 赵岩[2,3] 边世强 杨云鹏 金佳成 黄逢春 CHONG Yan;CHEN Guan;MENG Xing-min;YUE Dong-xia;ZHANG Yi;GUO Fu-yun;LIYa-jun;ZENG Run-qiang;ZHAO Yan;BIAN Shi-qiang;YANG Yun-peng;JIN Jia-cheng;HUANG Feng-chun(College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000.China;Gansu Technology Innovation Centre for Environmental Geology and Gcohazard Prevention,Lanzhou 730000,China;School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Western Chinu's Environmental Systems with the Minisiry of Education,Lanzhou 730000,China;Geological Environmental Monitoring Institute of Giansu Province,Lanchou 730050,China)

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]甘肃省环境地质与灾害防治技术创新中心,兰州730000 [3]兰州大学地质科学与矿产资源学院,兰州730000 [4]西部环境教育部重点实验室,兰州730000 [5]甘肃省地质环境监测院,兰州730050

出　　处：《兰州大学学报（自然科学版）》2022年第3期372-384,共13页Journal of Lanzhou University(Natural Sciences)

基　　金：国家重点研发计划课题(2018YFC1504704;2017YFC1501005);甘肃省重点研发计划项目(20YF8FA074);甘肃省科技重大专项计划项目(19ZD2FA002);国家自然科学基金重点项目(42130709);国家自然科学基金面上项目(42077230);甘肃省科技计划项目(18YF1WA114)。

摘　　要：以舟曲立节滑坡-泥石流灾害链为例,在快速探测滑坡变形特征与内部结构的基础上,分析立节滑坡-泥石流的成灾模式,基于数值模拟开展不同情景下灾害链的危险性定量预测,建立“光学遥感回溯分析-地球物理快速探测-数值模型定量评价”的滑坡-泥石流灾害链危险性综合评价方法,可为青藏高原及周边地区类似灾害链风险预测与应急处置提供参考.立节滑坡是受断裂带控制的黄土-碎石土堆积层滑坡,滑坡崩解滑塌区松散滑坡体和堆积区坡面、沟道堆积物是北山沟泥石流的主要物源,被地表径流侵蚀夹带转化为泥石流,形成滑坡-泥石流灾害链,对沟口立节镇造成严重威胁.为评价可能发生的滑坡-泥石流灾害链效应,利用MassFlow与BASEMENT综合数值建模方法,对滑坡的堆积以及不同降雨情景下可能形成的泥石流的流量、流速、堆积情况进行评价预测,结果显示,假设滑坡强度降低后,有约3.52×105m3滑坡物质极易转化为泥石流,在极端降雨条件下会出现泥石流堵江灾害.With the Lijie landslide-debris flow as a case study, the transformation mechanism was analyzed by detecting the landslide body’s deformation characteristics and internal structure, and a multi-hazards prediction carried out through a numerical simulations approach. The integrated method proposed in this paper, i.e. a backtracking analysis of the optical imagery-rapid detection via geophysical prospectingquantitative prediction through a numerical simulation, can provide a reference for risk prediction and emergency response to similar disaster chains in the Qinghai-Tibet Plateau and other regions. The Lijie landslide with loess and gravel soil is controlled by faults. The loose material of landslide body, channel deposition and slop deposition can be discriminated as the supply source for debris flows in Beishan Gully. Those materials are entrained by the surface runoff and transformed into a debris flow, forming a landslide-debris flow disaster chain and posing a serious threat to Lijie Town at the mouth of the gully.To evaluate the disaster chain effect of the landslide-debris flow, an integrated numerical modeling method including MassFlow and BASEMENT was used to predict the landslide runout under the residual strength, debris flows velocity, discharge and deposits of various recurrence intervals. The results showed that there were about 3.52×105m3of landslide material which can be easily converted into a debris flow when the material strength is reduced, and the debris flow will block the river under extreme rainfall conditions. This prediction result supported the rescue and relief work regarding the disasters chain.

关 键 词：滑坡 泥石流 灾害链 危险性预测 数值模拟 

分 类 号：P642[天文地球—工程地质学]