Risk Assessment Of Geological Hazard After Earthquake In Xiaojin Country

The5.12Wenchuan earthquake caused the4000death toll,8000people injured,hundreds of people lost,130,000houses collapsed, and the infrastructure such as water,electricity, roads and communication destroyed, all of which is worth20billion RMB.The earthquake not only caused the death toll and losses, but also induce secondarydisaster. The fault of Wenchuan earthquake lies between Yingxiu and Beichuan. whichcontain the central and front range fault. The geoenvironment was heavily damagedafter the earthquake and high frequent aftershocks which cause the rockfall, earthsplitand mountain loosen. The landslides, rockfall and debris flow were triggered by theheavy rain. So it’s essential to assess the geohazard risk, manage the information andtake precautions against the disaster.The assessment of5.12earthquake induced disaster is based on field researchand remote sensing interpretation of the characteristic and distribution of geohard inXiaojinxian county. and using GIS spatial analysis method, to Xiaojinxian Provincegeological disaster risk assessment.In view of this, this article mainly in this area do a related discussion, get thefollowing conclusions:(1)Compared with the traditional field research, the RS, which analysis allelements of disaster and afford favorable materials, has the advantage of highresolution and high speed obtainability. Landslide, rockfall and debris flow areinterpreted in this dissertation which contain417geohazard spots, most of which arelandslides.(2)The geohard is affected by the geoenvironment condition, which mainlyareTopography, geomorphology, tectonics, stratum, lithology, engineering geologicalpetrofabrics, hydrology, precipitation and vegetation. The first five of the elements arebasic condition of geohazard, the others are triggered factor.(3)The sensitivity analysis of the geohazard and the other related elements isbased on GIS, the elements in which are Topography, geomorphology, tectonics,stratum, lithology, hydrology and precipitation. The picture of dangerous assessment of geological disaster is drew based onanalytic hierarchy process to set up the geohazard assessment model and GIS’s spatialanalysis function to conduct overlay analysis.(4)The results of the assessment illustrate the earthquake induced geohazrddistribution and the correspondence between geohazard distribution and the density ofgeohazard Spots. The reliability of assessment system and index factor is proved.(5)Prevention and reduction of geological hazards are proposed based on theassessment of geohazard dangerousness. Suggestion and precautions are proposed forfollowing geohazard control project.