Assessment Of The Geological Risk Based On Gis Of Qiaojia County In Yunnan Province

In August 3,2014,an earthquake with a 6.5 magnitude struck Ludian County.The study area of Qiaojia county is adjacent to Ludian county,which is one of the most seriously affected areas in this earthquake.413.1 thousand people affected in this event,78 people died and cost economic lost for 5.747 billion Yuan.The hazard spots were increased from 300 before the earthquake to more than 500 after the earthquake.Doing the geological disaster risk rating fits the need of the geological disaster prevention,it also has important significance for reducing casualties and property losses in this county.This paper takes 533 hazard spots in Qiaojia county as the research object,through field investigations and data collections,get basic conditions about geological disasters,the geological environment and geographical factors.It Also Analyze the distribution characteristics and influencing factors of geological disasters.By GIS technology,using the method of information,the analytic hierarchy process and fuzzy comprehensive evaluation method to complete the geological disaster risk assessment in Qiaojia County.Through the risk assessment,geological disaster prevention and control measures are put forward.Main work are as follows:(1)Based on the geographical and geological environment conditions of Qiaojia,analyzes the distribution characteristics and influencing factors of geological disasters in the study area by GIS.(2)This paper selected seven indicators like elevation,slope,fault,rock group,rainfall and earthquake for the risk evolution.By using GIS software and combination of information method and AHP(analytical hierarchy process)method,the study area can be divided into three parts: high geological hazard,medium and low.(3)This paper used four indicators include population density,land density,road density and GDP density for the vulnerability evolution.In the villages of the evaluation unit,and FCE(fuzzy comprehensive evolution method),the study area is divided into geological hazard of high,medium,and low.(4)Combined with evolution results in geological hazard and vulnerability assessment in Qiaojia county,the theoretical model Risk=Hazard*Vulnerability is used in this paper.The study area is divided into three areas: high risk,medium risk and low risk of geological disaster.(5)According to the risk assessment,some specific short-term and long-term measures are put for the focus,the second-rate focus and general control area.