GIS Based Four Zones of GEOHAZARD SUSCEPTIBILITY Degrees for FENGXIAN COUNTY in Qinling Mountains of SHAANXI PROVINCE

Regional geo-hazard susceptibility assessment is the basis for early warning of geo-hazards.To develop assessment methods of geo-hazard susceptibility in Qinling Mountain area,the distribution and the main influencing factors of geo-hazards in Fengxian county,Shaanxi province are comprehensively analyzed based on the geo-hazard investigation and mapping of 1 :50000 scale.With GIS and information model,the geo-hazard susceptibility evaluation of the whole area of Fengxian County is carried out.According to the result,the distribution of geo-hazard is mainly affected by river erosion,vegetation coverage and human activities.The whole area can be divided into four categories: the high grade area,which covers 190.3km2,accounting for 6.0% of the total study area; the medium grade area,which covers 642.0km2,accounting for 20.1%; the low grade area,which is measured 1314.5km2,taking up for 41.2%; and the stable area that is measured 1040.1km2,taking up for 32.6%.The results can provide a basis for construction layout and geo-hazard prevention and reduction in Fengxian County and also provide the guideline for geo-hazard susceptibility zonation in other counties of Qinling Mountain area.