Geological hazard risk assessment and suggestions for risk control in chaya county, eastern Tibet
-
摘要: 以藏东察雅县城为研究区,选取高程、坡度、坡形、坡向、斜坡结构、地层、距断层距离7个评价指标,运用证据权重法,构建了地质灾害易发性评价模型。以四种降雨频率(10%、5%、2%、1%)下的年最大日降雨量作为动态诱发因子,建筑人口和交通设施作为承灾体,评价了地质灾害的动态风险性。结果表明,除围绕县城场镇两侧的斜坡以高风险和极高风险区为主外,研究区其他区域以中、低风险为主。随着降雨频率的降低,区内高风险区与极高风险区面积同比最大增长25.81%和0.44%;低风险区与中风险区面积最大下降幅度分别为20.03%和6.52%。基于风险评价结果,提出考虑不同降雨频率的地质灾害风险源头管控方法,具体为:针对10%、5%、2%和1%四种降雨频率下的极高风险区,建议分别采取工程治理、工程治理/专业监测、专业监测、专业监测/群专结合的管控手段;针对1%降雨频率下的高风险与中风险区,建议采取的风险管控措施为群专结合与群测群防。该风险管控体系考虑了不同降雨频率下斜坡的动态风险,可精细化提高山区城镇地质灾害风险的管控水平。Abstract: Chaya County Town in eastern Tibet was selected as the research area for the susceptibility assessment of geological disasters. Seven evaluation indexes, including elevation, slope grade, slope form, slope direction, slope structure, stratum, and distance from fault, were selected to construct an evaluation model of geological disaster susceptibility using the evidence weight method. Using the annual maximum daily rainfall under four rainfall frequencies (10%, 5%, 2%, 1% ) as the dynamic inducing factor and building population and transportation facilities as the hazard bearing body, the dynamic risk of geological hazards in the town was evaluated. The results show that except for the slopes on both sides of the county town, which were mainly high-risk and extremely high-risk areas, other areas in the research area were mainly medium and low-risk areas. As the frequency of rainfall decreased, the areas of high-risk and extremely high-risk areas increased by a maximum of 25.81% and 0.44%, respectively, while the areas of low-risk and medium-risk areas decreased by a maximum of 20.03% and 6.52%, respectively. Based on the risk assessment results, a method for controlling the source of geological hazard risk considering different rainfall frequencies was proposed. Specifically, for the extremely high-risk areas under the four rainfall frequencies of 10%, 5%, 2% and 1%, it is recommended to adopt engineering management, engineering management / professional monitoring, professional monitoring, and professional monitoring / combination of mass monitoring and professional monitoring. For the high-risk and medium-risk areas under a 1% rainfall frequency, the recommended risk control measures were the combination of mass monitoring and professional monitoring, and the combination of mass supervision and mass prevention.The risk management and control system accounted for the dynamic risks of slopes under different rainfall frequencies, which would enhance the management and control of geological hazard risks in mountainous urban areas in a refined manner.
-
表 1 研究区承灾体易损性赋值表
Table 1. Vulnerability assessment table for hazard-bearing bodies in the study area
承灾体类型 分类 易损性 对应属性字段 对应属性 建筑及
人口类型>1000人 0.9 类型 密集多层居住区 0.9 类型 医院 0.9 类型 学校 100−1000人 0.8 类型 密集低矮居住区 0.7 类型 寺庙 0.6 类型 加油站 0.8 类型 行政办公区 10−100人 0.4 类型 基础设施区 0.2 类型 一般居住区 0.3 类型 商业设施区 <10人 0.1 类型 临时居住区 0.1 类型 农业区 0.1 类型 荒地区 0.1 类型 避难场地区 交通设施 县级公路 0.3 GB 420301 专用公路 0.2 GB 420400 其他公路 0.1 GB 420800 城市道路 0.2−0.3 GB 430501、430501 乡村道路 0.0−0.1 GB 440100、440300 表 2 地质灾害风险等级划分表
Table 2. Risk level classification table for geological disasters
需替换 坡度 需替换 坡向 需替换 地层 需替换 高程 1 坡度 0.020 1 坡形 0.032 -0.001 1 坡向 0.069 0.168 0.026 1 斜坡结构 0.134 0.128 0.021 0.258 1 地层 −0.316 −0.148 0.079 −0.030 −0.110 1 距断层距离 0.343 0.080 0.023 0.114 0.016 −0.172 1 表 3 各指标因子间的相关性统计
Table 3. Statistical table for correlation among each index factor
高程 坡度 坡形 坡向 斜坡结构 地层 距断层
距离高程 1 坡度 0.020 1 坡形 0.032 −0.001 1 坡向 0.069 0.168 0.026 1 斜坡结构 0.134 0.128 0.021 0.258 1 地层 −0.316 −0.148 0.079 −0.030 −0.110 1 距断层距离 0.343 0.080 0.023 0.114 0.016 −0.172 1 表 4 研究区各证据因子权重值表
Table 4. Summary table of weighted values of each featured factor in the study area
影响因子及分级 ${ {W} }_{ {i} }^{ {+} } $ ${ {W} }_{ {i} }^{-}$ $W_f $ 高程(m) 3000−3500 0.2483 −0.2112 0.4596 3500−4000 −0.1064 0.0935 −0.1999 4000−4500 −0.9514 0.0689 −1.0203 坡度 <10° −0.7271 0.0691 −0.7962 10-20° 0.2796 −0.0750 0.3546 20-30° 0.1089 −0.0616 0.1705 30-40° 0.0396 −0.0146 0.0542 40-50° −0.6449 0.0374 −0.6823 50-60° −1.1721 0.0095 −1.1816 >60° −4.3125 0.0014 −4.3139 坡向 平面 0.5463 −0.0792 0.6256 北 1.5770 −0.2022 1.7792 东北 1.0220 −0.2189 1.2409 东 −0.1133 0.0128 −0.1260 东南 −0.6638 0.0553 −0.7192 南 −2.3082 0.1450 −2.4532 西南 −3.3031 0.1624 −3.4655 西 −1.5441 0.1140 −1.6580 西北 0.2250 −0.0326 0.2575 坡型 凹形 −0.2290 0.0491 −0.2780 凸型 0.1337 −0.2348 0.3685 直线型 −0.2392 0.0546 −0.2938 斜坡结构 河谷 −7.4634 0.0526 −7.5160 顺向飘倾坡 −2.6380 0.0150 −2.6530 顺向层面坡 −0.7848 0.0088 −0.7936 顺向伏倾坡 −0.5073 0.0425 −0.5498 斜顺向坡 −0.5159 0.0577 −0.5737 横向坡 −0.2863 0.0976 −0.3839 斜逆向坡 0.3733 −0.1057 0.4790 逆向坡 0.5425 −0.2225 0.7649 地层 T3d 1.3006 −0.1359 1.4366 J2d −2.5677 0.2464 −2.8140 J2c 0.0000 0.0007 −0.0007 J1w 0.1942 −0.5731 0.7673 Qhel −3.7152 0.0512 −3.7664 距断层距离 <200 m 0.5295 −0.0395 0.5690 200−500 m 0.8501 −0.1114 0.9614 500−1000 m 0.8722 −0.2073 1.0795 1000−2000 m 0.4909 −0.1912 0.6820 >2000 m −1.6415 0.6672 −2.3087 表 5 研究区不同降雨频率下的年最大日降雨量估算结果
Table 5. Estimation results of Annual Maximum Daily Rainfall under Different Rainfall Frequencies in the study area
P/% KP H24P/mm 1 1.436 55.14 2 1.374 52.76 5 1.286 49.38 10 1.212 46.54 -
[1] 齐信,唐川,陈州丰,等. 地质灾害风险评价研究[J]. 自然灾害学报,2012,21(5):33 − 40. [QI Xin,TANG Chuan,CHEN Zhoufeng,et al. Research of geohazards risk assessment[J]. Journal of Natural Disasters,2012,21(5):33 − 40. (in Chinese with English abstract) doi: 10.13577/j.jnd.2012.0506 [2] COROMINAS J,VAN WESTEN C,FRATTINI P,et al. Recommendations for the quantitative analysis of landslide risk[J]. Bulletin of Engineering Geology and the Environment,2014,73(2):209 − 263. [3] 吴树仁,石菊松,张春山,等. 地质灾害风险评估技术指南初论[J]. 地质通报,2009,28(8):995 − 1005. [WU Shuren,SHI Jusong,ZHANG Chunshan,et al. Preliminary discussion on technical guideline for geohazard risk assessment[J]. Geological Bulletin of China,2009,28(8):995 − 1005. (in Chinese with English abstract) doi: 10.3969/j.issn.1671-2552.2009.08.001 [4] 康婧,王伟伟,程林,等. 基于模糊数学方法的海岛地质灾害风险评价—以长兴岛为例[J]. 海洋环境科学,2016,35(6):861 − 867. [KANG Jing,WANG Weiwei,CHENG Lin,et al. Risk assessment of geological hazard based on fuzzy mathematics—A case study of Changxing Island[J]. Marine Environmental Science,2016,35(6):861 − 867. (in Chinese with English abstract) doi: 10.13634/j.cnki.mes.2016.06.035 [5] 李天华,袁永博. 地震重灾区诱发次生地质灾害风险评价研究[J]. 地震工程学报,2018,40(1):111 − 115. [LI Tianhua,YUAN Yongbo. Risk assessment of secondary geological disasters induced in an earthquake-stricken area[J]. China Earthquake Engineering Journal,2018,40(1):111 − 115. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-0844.2018.01.111 [6] 罗路广,裴向军,谷虎,等. 基于GIS的“8·8”九寨沟地震景区地质灾害风险评价[J]. 自然灾害学报,2020,29(3):193 − 202. [LUO Luguang,PEI Xiangjun,GU Hu,et al. Risk assessment of geohazards induced by “8·8” earthquake based on GIS in Jiuzhaigou scenic area[J]. Journal of Natural Disasters,2020,29(3):193 − 202. (in Chinese with English abstract) doi: 10.13577/j.jnd.2020.0321 [7] 张茂省,薛强,贾俊,等. 山区城镇地质灾害调查与风险评价方法及实践[J]. 西北地质,2019,52(2):125 − 135. [ZHANG Maosheng,XUE Qiang,JIA Jun,et al. Methods and practices for the investigation and risk assessment of geo-hazards in mountainous towns[J]. Northwestern Geology,2019,52(2):125 − 135. (in Chinese with English abstract) doi: 10.19751/j.cnki.61-1149/p.2019.02.013 [8] 王佳佳. 三峡库区万州区滑坡灾害风险评估研究[D]. 武汉: 中国地质大学WANG Jiajia. Landslide Risk Assessment in Wanzhou County, Three Gorges Reservoir[D]. Wuhan: China University of Geosciences. (in Chinese with English abstract) [9] 王芳. 万州区滑坡灾害风险评价与管理研究[D]. 武汉: 中国地质大学WANG Fang. Study on risk assessment and management of landslide in Wanzhou district[D]. Wuhan: China University of Geosciences. (in Chinese with English abstract) [10] 肖婷. 三峡库区万州区及重点库岸段滑坡灾害风险评价[D]. 武汉: 中国地质大学XIAO Ting. Landslide risk assessment in Wanzhou district and A key section, three gorges reservoir[D]. Wuhan: China University of Geosciences. (in Chinese with English abstract) [11] 周超,常鸣,徐璐,等. 贵州省典型城镇矿山地质灾害风险评价[J]. 武汉大学学报(信息科学版),2020,45(11):1782 − 1791. [ZHOU Chao,CHANG Ming,XU Lu,et al. Risk assessment of typical urban mine geological disasters in Guizhou Province[J]. Geomatics and Information Science of Wuhan University,2020,45(11):1782 − 1791. (in Chinese with English abstract) [12] 熊小辉,汪长林,白永健,等. 基于不同耦合模型的县域滑坡易发性评价对比分析—以四川普格县为例[J]. 中国地质灾害与防治学报,2022,33(4):114 − 124. [XIONG Xiaohui,WANG Changlin,BAI Yongjian,et al. Comparison of landslide susceptibility assessment based on multiple hybrid models at County level:A case study for Puge County,Sichuan Province[J]. The Chinese Journal of Geological Hazard and Control,2022,33(4):114 − 124. (in Chinese with English abstract) [13] 解明礼,巨能攀,刘蕴琨,等. 崩塌滑坡地质灾害风险排序方法研究[J]. 水文地质工程地质,2021,48(5):184 − 192. [XIE Mingli,JU Nengpan,LIU Yunkun,et al. A study of the risk ranking method of landslides and collapses[J]. Hydrogeology & Engineering Geology,2021,48(5):184 − 192. (in Chinese with English abstract) doi: 10.16030/j.cnki.issn.1000-3665.202007011 [14] 范强,巨能攀,解明礼,等. 2017年九寨沟MS7.0地震前后地质灾害风险对比[J]. 地震研究,2019,42(3):419 − 427. [FAN Qiang,JU Nengpan,XIE Mingli,et al. Comparation of geological hazard risks before and after Jiuzhaigou MS7.0 earthquake in 2017[J]. Journal of Seismological Research,2019,42(3):419 − 427. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-0666.2019.03.016 [15] 关朝阳,李章国. 西藏昌都地质灾害特点及防治对策[J]. 中国地质灾害与防治学报,2018,29(2):104 − 107. [GUAN Chaoyang,LI Zhangguo. Characteristics and prevention measures of geological hazards in Changdu City,Tibet[J]. The Chinese Journal of Geological Hazard and Control,2018,29(2):104 − 107. (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2018.02.17 [16] 范强,巨能攀,向喜琼,等. 证据权法在区域滑坡危险性评价中的应用—以贵州省为例[J]. 工程地质学报,2014,22(3):474 − 481. [FAN Qiang,JU Nengpan,XIANG Xiqiong,et al. Landslides hazards assessment with weights of evidence—A case study in Guizhou,China[J]. Journal of Engineering Geology,2014,22(3):474 − 481. (in Chinese with English abstract) doi: 10.13544/j.cnki.jeg.2014.03.017 [17] 郭长宝,唐杰,吴瑞安,等. 基于证据权模型的川藏铁路加查—朗县段滑坡易发性评价[J]. 山地学报,2019,37(2):240 − 251. [GUO Changbao,TANG Jie,WU Ruian,et al. Landslide susceptibility assessment based on WOE model along Jiacha—Langxian County section of sichuan—tibet railway,China[J]. Mountain Research,2019,37(2):240 − 251. (in Chinese with English abstract) doi: 10.16089/j.cnki.1008-2786.000418 [18] 胡燕,李德营,孟颂颂,等. 基于证据权法的巴东县城滑坡灾害易发性评价[J]. 地质科技通报,2020,39(3):187 − 194. [HU Yan,LI Deying,MENG Songsong,et al. Landslide susceptibility evaluation in Badong County based on weights of evidence method[J]. Bulletin of Geological Science and Technology,2020,39(3):187 − 194. (in Chinese with English abstract) [19] 刘传正. 崩塌滑坡灾害风险识别方法初步研究[J]. 工程地质学报,2019,27(1):88 − 97. [LIU Chuanzheng. Analysis methods on the risk identification of landslide disasters[J]. Journal of Engineering Geology,2019,27(1):88 − 97. (in Chinese with English abstract) doi: 10.13544/j.cnki.jeg.2019-009 [20] 地质灾害风险调查评价技术要求(1∶50000)[S]. 中国地质调查局, 2020Technical guide for geohazard risk survey and evaluation(1∶50000)[S]. China Geological Survey, 2020. [21] 张俊,殷坤龙,王佳佳,等. 三峡库区万州区滑坡灾害易发性评价研究[J]. 岩石力学与工程学报,2016,35(2):284 − 296. [ZHANG Jun,YIN Kunlong,WANG Jiajia,et al. Evaluation of landslide susceptibility for Wanzhou district of Three Gorges Reservoir[J]. Chinese Journal of Rock Mechanics and Engineering,2016,35(2):284 − 296. (in Chinese with English abstract) doi: 10.13722/j.cnki.jrme.2015.0318 [22] CHUNG C,FABBRI A. Probabilistic prediction models for landslide hazard mapping[J]. Photogrammetric Engineering and Remote Sensing,1999,65:1389 − 1400. -