基于不同地质环境分区的重庆市滑坡降雨阈值模型研究  

Threshold model of landslide rainfall in Chongqing based on different geological environment zones

作　　者：谢洋义 殷坤龙[1] 杜娟 刘书豪 邬礼扬 刘谢攀 XIE Yangyi;YIN Kunlong;DU Juan;LIU Shuhao;WU Liyang;LIU Xiepan(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China;Northwest Electric Power Design Institute Co.,Ltd.,China Power Engineering Consulting Group,Xi'an 710075,China)

机构地区：[1]中国地质大学(武汉)工程学院,武汉430074 [2]中国地质大学(武汉)环境学院,武汉430074 [3]中国电力工程顾问集团西北电力设计院有限公司,西安710075

出　　处：《地质科技通报》2025年第1期126-137,共12页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(42172318)。

摘　　要：考虑区域历史滑坡的降雨特征与地质环境,构建合理的降雨阈值模型,对区域滑坡灾害的预测预报十分重要。以重庆市2013-2021年的1368个降雨型滑坡为研究对象,基于详细的滑坡编录数据和区域地质环境资料,划分降雨事件,构建滑坡样本库。利用随机森林(RF)算法,建立了当日激发降雨量-前期有效降雨量(Rd-Rp)降雨阈值模型,基于概率分级划分了不同预警等级。以中等预警概率按孕灾环境、工程岩组、土地利用和土壤类型4种地质环境分别构建了19个临界降雨阈值判据。结果表明:Rd-Rp阈值模型能够很好地反映当日激发降雨量和前期有效降雨量对滑坡发育的影响,且前期有效降雨量在滑坡诱发中占主导作用。不同的地质环境类型对降雨因子的敏感性不同,地质构造、岩土体工程性质、植被覆盖以及土壤性质等对滑坡发育有重要影响。以坚硬岩为主的岩组阈值高于以软弱岩为主的岩组,林地的阈值大于耕地,受人类工程活动破坏严重的区域阈值会降低。利用随机森林方法为重庆市不同地质环境分区建立了降雨阈值判据,本研究可为重庆市降雨型滑坡的气象预警管理提供新的思路与借鉴依据。[Objective]Considering the rainfall characteristics and geological environment of regional landslides,constructing a reasonable rainfall threshold model is crucial for the prediction and forecasting regional landslide disasters.[Methods]This study takes 1368 rain-induced landslides in Chongqing from 2013 to 2021 as the research object.Based on detailed landslide data and regional geological environment information,rainfall events were divided and a landslide sample database was constructed.Using the random forest(RF)algorithm,a rainfall threshold model of the day's triggered rainfall-previous rainfall-previous effective rainfall(Rd-Rp)was established,and different warning levels were classified based on probability grading.Based on the medium early warning probability,19 threshold criteria for critical rainfall were constructed according to four geological environments:the disaster-prone environment,engineering rock group,land use,and soil type.[Results]The results show that the Rd-Rp threshold model can effectively reflect the impact of the daily excitation rainfall and the early effective rainfall on landslide development,and that early effective rainfall plays a dominant role in landslide induction.Different geological environment types show different sensitivities to rainfall factors,and geological structures,engineering properties of rock and soil masses,vegetation coverage,and soil properties have significant effects on landslide development.The threshold of rock formations dominated by hard rocks is higher than that dominated by weak rocks,and the threshold of forest land is greater than that of cultivated land.The threshold of areas severely damaged by human engineering activities will decrease.[Conclusion]This study can provide new ideas and references for the meteorological early warning management of rainfall-related landslide disasters in Chongqing.

关 键 词：降雨型滑坡 降雨阈值 有效降雨量 随机森林 地质环境分区 重庆市 

分 类 号：P642.22[天文地球—工程地质学]