USE OF GIS IN REGIONAL RISK ASSESSMENT OF EARTHQUAKE INDUCED LANDSLIDESA CASE STUDY OF EARTHQUAKE INDUCED LANDSLIDES IN LONGLING IN 1976

In West China,intense earthquakes occur frequently,because of its complex geological and geomorphological conditions,hence the earthquake-induced landslide become one of the most severe seismic hazards there.In this paper a technique for the risk assessment of seismic landslide hazard using GIS approach is developed.The method has been applied to the real case in Longling county,Yunnan Province,where a strong earthquake(M=7.3) which triggered lots of landslides occurred in 1976.With the application of GIS,the relationships between earthquake-induced landslide activity and a number of parameters including lithology,tectonic,site intensity,slope angle,etc.are analyzed.And furthermore,the risk of seismic landslide hazard for this region is assessed using the comprehensive index method.The occurrence of landslide is the result of all factors combination.In the seismic landslide hazard map generated accordingly,it is found that almost all landslides occur in the places which have been grouped as high risk areas.