“5.12”汶川地震次生山地灾害的分布与特点

Distribution and Characteristics of Mountain Hazards Induced by the Earthquake of May 12 in Wenchuan,China

"5.12"汶川地震的重灾区,主要分布在龙门山高山峡谷区和四川盆地深丘区等地,行政区划上涉及四川省的成都市、绵阳市、德阳市、广元市、阿坝藏族羌族自治州,甘肃省的陇南市,陕西省的汉中市等的山区,面积大于10×104km2。强烈地震除直接造成众多人员伤亡和各种设施被毁外,还在山区引发了大量次生山地灾害,形成灾害叠加,导致灾情更加严重。次生山地灾害主要沿龙门山地震断裂带集中分布和沿河谷两岸山坡分布,具有下列特点:1.类型多样,包括崩塌、滑坡、滚石、堰塞湖、泥石流等;2.数量上以滚石、崩塌、滑坡为主;3.导致了大量人员伤亡;4.堰塞湖主要由地震滑坡、崩塌形成;5.泥石流活动具滞发性,地震直接激发的泥石流仅一处;6.对生态环境破坏极大;7.加剧了防洪形势的严峻性;8.主要沿龙门山断裂带活动;9.活动强弱与地震烈度大小关系密切。

The earthquake-hit regions in Wenchuan of Sichuan,China mainly distribute in the Longmenshan Mountains and hill area of the Sichuan Basin edge,where are mountain canyon regions.In the administrative regionalization,the earthquake-hit regions involves mountain area of Chengdu,Mianyang,Deyang,Guangyuan,the Aba Tibetan and Qiang National Autonomous Prefecture of Sichuan Province,Longnan of Gansu Province and Hanzhong of Shanxi Province and so on,the area is bigger than 10×104 km2.The earthquake besides has caused the numerous personnel casualties and each kind of facility directly is destroyed,but also has induced a lot of mountain hazards in there,forming hazards to superimpose and hazards to be more serious.Mountain hazards induced by Earthquake distribute mainly along Longmenshan Mountains earthquake zones and rivers both banks hillside.They have the following characteristics：1.the type of mountain hazards are diverse,including collapse,landslide,rockfall,imprisoned lake,debris flow and so on;2.in quantity by collapses,landslides,rockfalls primarily;3.have caused many personnel casualty;4.the imprisoned lake mainly by the earthquake landslides and the collapses forms;5.debris flow activity has stagnates sends the nature,earthquake only directly caused a debris flow;6.pair of ecological environment destruction is enormous;7.causes the flood prevention situation to be more stern;8.occurs intensely along Longmenshan Mountains fault zones;9.the active strong and the weak and the earthquake intensity size relations are close.