Risk Assessment Of Geologic Hazards Along G318 Road From Lhasa To Nimu

318 national road around Lhasa is facing the potential threat of geological hazards because of complex geological condition and changing plateau climate.So parts of it from Lhasa to Nimu is researched by application of field geological survey,engineering geological analogy,analytic hierachy process and fuzzy comprehensive evaluation model.Geological hazard characteristic and distribution law are summarized on the basis of analyzing field data about 61 geological hazards.Moreover,susceptibility assessment and hazard zonation are delimitated.The results are as follows:(1)Summarized geological characteristic,temporal and spatial distribution by analyzing geotectonics,topography,landform,lithology,neotectonic movement,climate and hydrology.(2)According to geological hazard assessment criterion,integrated index system of rockfall,debris flow,unstable slope and regional scale are respectively established by utilizing engineering geological analogy and comparison method.And the weight of index are calculated by applying AHP.(3)By distinguishing rate of contribution and "cooperation relationship" between index,different fuzzy comprehensive evaluation model are used in hazard assessment.Finally,the results is compared with qualitative evaluation.(4)After studying influencing factors of geological disasters,the index "freeze-thawing"and "deformation" are classified qualitatively.