摘要
基于滑坡发生成因选取评价指标,设计客观、合理的评价和分级方法,实现区域滑坡灾害危险性评价对防御滑坡灾害和准确预警具有现实意义。基于现有滑坡危险性评价中,评价指标欠全面、评价指标分级偏主观、评价结果无法直接衡量出不同因子对区域整体及各危险区滑坡影响程度大小的现状,以滑坡灾害严重的重庆万州区为例,在充分考虑评价因子合理性的前提下,应用客观划分评价因子等级的证据权法,对区域滑坡灾害的危险性进行评价,并通过结合滑坡危险性敏感程度指数(S_(W))、创建的滑坡危险性影响程度指数(S_(I))及不同危险区影响程度指数(H_(W)),量化各评价因子整体对区域滑坡发生的敏感程度和影响程度,以及对不同危险区的影响程度的差异,为降低区域滑坡危险性提供更准确和针对性的理论参考,对提高区域滑坡灾害的有效防御能力具有重要意义。研究表明:(1)经独立性检验确定了剔除地形起伏度的万州区滑坡灾害危险性评价指标体系,该评价体系较全面概括了滑坡发生成因。(2)在评价指标初分级的基础上,结合证据权值、滑坡面积比和分级面积进行基于证据权法的评价指标终分级,实现证据权法支持下的区域滑坡危险性评价,评价结果经成功率曲线法验证,精度达72%,从指标选取和评价精度上体现出本研究方法的可靠性。(3)S_(W)和S_(I)指数分析得出,高程、道路距离、多年平均降雨量因子的区域整体敏感程度和影响程度均居前三,但其余因子在敏感程度和影响程度的排序上表现出差异性,说明S_(I)指数创建的必要性和科学性。(4)H_(W)指数说明,高、中和低危险区滑坡评价因子表现出与区域整体一致的影响程度特征,但较高危险区以道路距离因子影响程度最大;较低危险区则以归一化植被指数的影响程度上升为第二位,体现出H_(W)指数构建必要性。(5)低危险区主要位于植被覆盖度较高的高海拔区,此处常绿阔叶林和针叶林对滑坡发生有着抑制作用;高危险区主要位于万州区人类活动集聚特征显著的主城区,沿长江及其支流分布,且降水量多集中在1213~1229 mm的低海拔区,该类区域应通过开展合理的减滑工程措施、抗滑支挡工程措施及绿化护坡等,实施工程治理措施,以达到降低区域滑坡危险性的目的。
Based on the factors contributing to landslide occurrence,a well-designed and objective evaluation system is proposed to assess and classify the hazard of regional landslide disasters,which holds practical significance for both landslide disaster prevention and accurate forecasting.This study highlights the limitations of existing landslide hazard evaluation methods,such as incomplete evaluation indicators,subjectivity in the classification of evaluation criteria,and the inability to directly measure the current impact of different factors on the overall region and different hazard landslide areas.Taking the severely landslide-prone Wanzhou District in Chongqing as an example,under the premise of fully considering the rationality of evaluation factors,an objective division of evaluation factor levels using the weights of evidence method is applied to assess the hazard of regional landslide disasters.By combining the landslide hazard sensitivity index(S_(W))and the newly created landslide hazard impact index(S_(I)),along with the impact index(H_(W))for different hazardous areas,the overall sensitivity and impact of each evaluation factor on regional landslide occurrence are quantified.Moreover,the differences in impact on different hazardous areas are measured.This approach provides more accurate and targeted theoretical references for reducing the hazard of regional landslides,and holds significant importance in enhancing the effective defense capability against regional landslide disasters.The study shows that:(1)the evaluation index system for landslide hazard evaluation in Wanzhou District,after removing the topographic relief factor through the test for independence,comprehensively captures the landslide causative factors.(2)Based on the initial grading of evaluation indicators,the final grading of evaluation indicators is achieved using the weights of evidence,landslide area ratio,and grading area,with the support of the weights of evidence method.This approach enables regional landslide hazard evaluation,and the evaluation results are validated through the success rate curve method,with an accuracy of 72%.Therefore,the reliability of evaluation method in this research is reflected through the favorable evaluation precision.(3)The analysis of S_(W)and S_(I)indices reveals that elevation,road distance,and multi-year average rainfall are the top three factors with the highest overall sensitivity and impact on the region for landslide occurrence.However,the remaining factors show variations in their rankings in terms of sensitivity and impact.The difference in the ranking results of evaluation indicators on two indices indicates the necessity and scientificity of the S_(I)index in this study.(4)The H_(W)index indicates that the evaluation factors for high,medium,and low hazard areas exhibit consistent characteristics with the overall regional landslide occurrence.However,in relatively high hazard areas,the road distance factor has the greatest impact.In contrast,in relatively low hazard areas,the normalized vegetation index shows the second-highest impact,indicating the effectiveness and scientific validity of the H_(W)index constructed in this study.(5)The low hazard areas are mainly located in high-altitude regions with higher vegetation coverage.Here,evergreen broad-leaved forests and coniferous forests play a suppressive role in the occurrence of landslides.On the other hand,the high hazard areas are primarily concentrated in the main urban areas of Wanzhou District,where human activities are significant.These areas are distributed along the Yangtze River and its tributaries,with higher precipitation levels concentrated in the low-altitude regions between 1213 mm to 1229 mm.For the high hazard areas,it is essential to implement appropriate measures to reduce the landslide hazard,such as undertaking proper landslide control engineering,anti-slide support measures,and slope greening.The implementation of these engineering measures will help mitigate the landslide hazard and achieve the goal of reducing the overall landslide hazard in the region.
作者
谢晓
卢晓宁
沈文宇
马启民
唐云辉
杨秋萍
刘明林
李实康
夏志业
XIE Xiao;LU Xiaoning;SHEN Wenyu;MA Qimin;TANG Yunhui;YANG Qiuping;LIU Minglin;LI Shikang;XIA Zhiye(College of Resources and Environment,Chengdu University of Information Technology,Chengdu,Sichuan 610225,China;Chongqing Institute of Meteorological Science,Chongqing 401147,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第S02期3936-3950,共15页
Chinese Journal of Rock Mechanics and Engineering
基金
基于北斗的面场景毫米级三维形变监测关键技术与应用示范(2021YFB3901400)
四川省社科“十四五”规划项目(SC22B155)
成都市科技局技术创新研发项目(2022-YF05-00620-SN)
关键词
边坡工程
滑坡
危险性评价
证据权法
GIS
slope engineering
landslide
hazard evaluation
weights of evidence
GIS
作者简介
谢晓(2000-),女,2022年毕业于成都信息工程大学地理信息科学专业,现为硕士研究生,主要从事滑坡灾害方面的研究工作。E-mail:736513794@qq.com;通讯作者:卢晓宁(1980-),女,现任副教授。E-mail:lxn@cuit.edn.cn
