摘要
基于对汶川8.0级地震同震地质灾害和震后5年来龙门山中北段地质灾害空间分布的刻画,对震后泥石流灾害空间分布及其控制因素进行分析,获得以下认识:震后泥石流集中分布在北川-映秀断裂上盘10 km范围以内,相对于同震崩塌、滑坡具有更明显的上盘效应。震后泥石流的空间分布主要受松散堆积物分布范围、地形地貌、岩性、降水等多种因素控制。其中同震崩塌、滑坡松散堆积物为震后泥石流的发生提供了重要的物质来源;地形地貌是控制震后泥石流发生的重要影响因素,为泥石流提供了势能和启动的空间条件;震后泥石流集中发生在前震旦系彭灌杂岩和古生界粉砂岩、砂岩等岩性分布区;降水是导致震后泥石流地质灾害发生的直接诱发因素。
On the basis of coseismic geological disasters of and spatial distribution of geological disasters char- acterizations of the northern section in Longmen in 5 years after Wenchuan M8.0 earthquake, debris flow disaster of earthquake spatial distribution and its control factors are analyzed. Results show that debris flows after the earth- quake distributed mainly 10km within the hanging wall in Beichuan-Yingxiu fault. Compared to the same earth- quake collapse, the landslides are of more obvious hanging wall effect. The spatial distribution of landslides after the earthquake is mainly influenced by a variety of physical distribution of loose deposits, topography, lithology, precipitation and other factors. The same occurrence earthquake collapse, landslide loose deposits for post earth- quake debris flow provide important material sources. The topography is the important factor that controls the occur- rence of debris flow, and it offers potential energy and the space condition of start-up for the debris flow. After the earthquake, debris flow occurs in the pre Sinian Pengguan complex and Paleozoic siltstone, sandstone lithologic distribution area. Precipitation is the direct factor that leads to the occurrence of debris flow.
出处
《灾害学》
CSCD
北大核心
2014年第2期38-41,共4页
Journal of Catastrophology
基金
国家自然科学基金面上项目“汶川地震驱动的崩塌、滑坡和泥石流的河流响应过程研究”(41172162)
关键词
汶川地震
震后
泥石流
空间分布
控制因素
Wenchuan Earthquake
post-seismic
debris flow
space distribution
controlling factor
