甘肃省白龙江流域降雨型潜在泥石流危险性预报模型  

Prediction model of potential debris flow hazard of rainfall type in Bailong River Basin,Gansu Province

作　　者：王高峰 高幼龙[2] 姚亚辉[2] 田运涛[2] 徐友宁[3] 孙秀娟[2] 李瑞冬[4] 何元宵 邓兵[2] 叶振南[2] 陈宗良[2] 郭宁[2] WANG Gaofeng;GAO Youlong;YAO Yahui;TIAN Yuntao;XU Youning;SUN Xiujuan;LI Ruidong;HE Yuanxiao;DENG Bing;YE Zhennan;CHEN Zongliang;GUO Ning(Chinese Academy of Geological Sciences,Beijing,100084,China;Center for Hydrogeology and Environmental Geology Survey,China Geology Survey,Baoding 071051,Hebei,China;Xi'an Geological Survey Center of China Geological Survey,Xi'an 710061,Shaanxi,China;Geo-Environment Monitoring Institute of Gansu Province,Lanzhou 730050,Gansu,China;Sichuan Geological Survey Institute,Chengdu 610081,Sichuan,China)

机构地区：[1]中国地质科学院,北京100084 [2]中国地质调查局水文地质环境地质调查中心,河北保定071051 [3]中国地质调查局西安地质调查中心,陕西西安710061 [4]甘肃省地质环境监测院,甘肃兰州730050 [5]四川省地质调查院,四川成都610081

出　　处：《中国地质》2022年第3期732-748,共17页Geology in China

基　　金：中国地质调查局地质调查项目(DD20160281、DD20190646、DD20221747)资助。

摘　　要：【研究目的】泥石流灾害是白龙江流域分布广泛并常引起群死群伤的重大地质灾害,准确评价泥石流活动规模及其危险度,是泥石流危险性预警预报的前提,合理构建危险性预报模型是泥石流防灾减灾的关键。【研究方法】本文以研究区历史泥石流案例和对应降雨资料为基础数据,采用统计分析方法,通过分析形成泥石流关键地质环境条件及其相互关系,构建了白龙江流域潜在泥石流危险度定量评价模型,提出了两类泥石流危险级别临界判别模式。【研究结果】结果表明:(1)以泥石流活动规模、沟床平均比降、流域切割密度、不稳定沟床比例为判断因子的泥石流危险度动态定量计算模型,能快速准确预测未来不同工程情景和降雨频率工况下泥石流危险度;(2)影响降雨型泥石流发生的地形条件由流域面积、10°~40°斜坡坡度面积比、沟床平均纵比降等组成,降雨条件主要由泥石流爆发前的24 h累积降雨量、触发泥石流1 h降雨量或10 min降雨量等组成;(3)依据30条典型泥石流沟危险度计算结果,获得泥石流危险性临界判别值,提出了降雨型潜在泥石流危险性1 h预报模型(Ⅰ类)和10 min预报模型(Ⅱ类),其中Ⅰ类模型高危险度以上泥石流预测精度大于87.5%,Ⅱ类模型中等危险度以上泥石流预测精度大于80%,而两类预报模型验证准确率为83.3%。【结论】研究成果为泥石流精准预警预报提供了技术支撑,对建立中小尺度泥石流实时化预警系统具有一定参考意义。This paper is the result of geological hazard survey engineering.[Objective]Debris flow is a major geological disaster widely distributed in Bailong River Basin and often causes mass casualties.Accurate evaluation of the scale and risk of debris flow is the premise of the early warning and prediction of debris flow.Reasonable construction of risk prediction model is the key to debris flow disaster prevention and reduction.[Method]Based on the reported debris flow cases and corresponding rainfall data in the study area,the quantitative evaluation model of potential debris flow risk in Bailong River Basin is constructed by analyzing the key geological environmental conditions and their relationship,and two kinds of critical discrimination models of debris flow risk level are proposed.[Results]The results show that:(1)The dynamic quantitative calculation model of debris flow risk degree with debris flow activity scale,average gradient of gully bed,watershed cutting density and unstable gully bed ratio can be used as judgment factors to quickly and accurately predict the risk degree of debris flow under different engineering scenarios and rainfall frequencies in the future;(2)The topographic conditions affecting the occurrence of rainfall type debris flow are composed of watershed area,slope area ratio of 10°-40°,average longitudinal ratio of gully bed,etc;the rainfall conditions are mainly composed of 24 h cumulative rainfall before the outbreak of debris flow,1 h rainfall or 10min rainfall triggering debris flow,etc;(3)Based on the risk calculation results of 30 typical debris flow gullies,the critical discrimination value of debris flow risk is obtained,and the 1h prediction model and 10min prediction model of potential debris flow risk of rainfall type are proposed.Among them,the prediction accuracy of debris flow above high risk of class Ⅰ model is greater than 87.5%,the prediction accuracy of debris flow above medium risk of class Ⅱ model is greater than 80%,and the verification accuracy of the two predic

关 键 词：泥石流 危险性预报模型 地形条件 降水条件 地质灾害调查工程 白龙江流域 甘肃省 

分 类 号：P642.23[天文地球—工程地质学]