汶川地震区地质灾害成生规律研究  

Regional assessment on geological disasters in “5.12”Wenchuan seismic area,China

作　　者：刘传正[1,2] 温铭生[1,2] 刘艳辉[1,2] 刘秋强[1,2] 顾笑筱[1,2] LIU Chuanzheng WEN Mingsheng LIU Yanhui LIU Qiuqiang GU Xiaoxiao(Consultative Centre for Geo-Hazard Emergency, MLR, Beijing 100081, China China Institute for Geo-Environment Monitoring, Beijing 100081, China)

机构地区：[1]国土资源部地质灾害应急指导中心,北京100081 [2]中国地质环境监测院,北京100081

出　　处：《水文地质工程地质》2016年第5期1-16,共16页Hydrogeology & Engineering Geology

基　　金：国家地质调查计划项目(1212011220125)

摘　　要：本项研究建立了2008年"5.12"汶川地震区62县域(面积约15×104km^2,地理精度1∶250 000,包括四川省48个县、甘肃省10个县和陕西省4个县)和中心区11县域(面积约3.1×104km^2,地理精度1∶50 000,包括四川省10个县、甘肃省1个县)的地质灾害信息系统。62县域地震前编录地质灾害4 913处,占总数的23.5%;地震直接引发10 173处,占总数的48.8%;地震后新发生5 779处,占总数的27.7%。11县域地震前编录地质灾害251处,占总数的3.5%;地震直接引发4 789处,占总数的66.7%;地震后新发生2 137处,占总数的29.8%。根据地质灾害区域发育度、潜势度、危险度、风险度和危害度等"五度"评价理论,分别研究了2008年"5.12"地震前历史积累、地震引发、地震后("5.12"地震后到2013年底)和前三者合计的现状等4个时段的地质灾害区域成生规律。根据地质灾害发育度指数计算结果,62县域地震前地质灾害高、中发育区面积占比11.5%,现状情况下相应的发育区面积占比增加到27.5%。11县域地震前地质灾害高、中发育区面积占比0.71%,现状情况下相应的发育区面积占比增加到11.82%,地震引发作用及其滞后效应是显著的。考虑地质灾害发育度指数、地形坡度、坡向、高程、地层岩组、水文地质、断层分布、地貌类型、地震烈度、年均降雨量、植被盖度、水系、交通线分布、地震作用、汛期降雨和日降雨等要素指标,分别计算出不同时段的地质灾害潜势度指数和不同引发条件下地质灾害危险度指数和风险度指数分布,并按极高、高、中、低4个等级分别评价和编制了相应的区划图。62县域地震前地质灾害高、中潜势区面积占比63.1%,现状情况下相应的面积占比增加到70.5%,地震作用造成地质环境条件显著恶化。11县域地震前地质灾害高、中潜势区面积占比1.21%,现状情况下相应的面积占比增加到18.94%,地质灾害易发区或敏感区面积In this paper, an information system is set up for geological disasters in the ＂5.12＂ Wenchuan earthquake region. The system consists area of 62 counties with scale 1：250 000 in geography which is of 15 ×10^4 km^2 , 48 counties in Sichuan province, 10 counties in Gansu province and 4 counties in Shaanxi province, and 11 counties in center area with scale 1：50 000 in geography which is of 3.1×10^4 km^2 , 10 counties in Sichuan province and 1 county in Gansu province. The inventory of geo-disasters in 62 counties includes 4 913 cases happened before the earthquake, 10 173 cases induced by the earthquake and 5 779 cases triggered by raining after earthquake, with 23.5% , 48.8% and 27.7% of total numbers, respectively. The inventory of geo-disasters in 11 counties includes 251 cases happened before the earthquake, 4 789 cases induced by the earthquake and 2 137 cases triggered by raining after earthquake, with 3.5%, 66.7% and 29.8% respectively. The regional assessment theory is applied with five grade indexes of geological disasters, i.e. developmental grade, potential grade, dangerous grade, risk grade and harmful grade indexes. The five grade indexes of geological disasters have been calculated for four periods, which are divided as before, instant, after and at present up to the end of 2013 according to timestamp of ＂5.12＂ Wenchuan earthquake in 2008. According to calculation results of the developmental grade indexes, the developmental area ratio of the high- middle grade was 11.5% before Wenchuan event, but increased to 27.5% at present after the earthquake in 62 counties. Similarly, the ratio was 0.71% before the earthquake, but increased to 11.82% at present after the earthquake in 11 counties, indicating distinctive seismic excitation and lagging effects. Selecting assessment factors as developmental grade index, landform gradient, slope exposure, stratigraphic layers, hydrogeology, fault density, topographic feature, seismic intensity, average annual precipitation, vegetation coverage, river s

关 键 词：“5.12”汶川地震 地质灾害 发育度 潜势度 危险度 风险度 危害度 

分 类 号：X141[环境科学与工程—环境科学]