Study on the risk assessment of geological disasters in Qinba mountain area—A case study of Hanzhong city
In an attempt to explore the distribution characteristics of geological disasters in Qinba mountain area where geological disasters happen frequently,this paper chooses Hanzhong city as the research area.According to the characteristics of eco-geological environment of Hanzhong city.nine impact factors,in-cluding elevation,slope,lithology,distance to fault structural belt,distance to river,distance to road,pre-cipitation,normalized difference vegetation index and land use type,were selected as the risk assessment in-dexes of geological disaster.The combination weight was synthesized by analytic hierarchy process and princi-pal components analysis,and the information value of each index was multiplied by the combination weight,and then the evaluation factor raster layers were overlaid and graded in ArcGIS spatial analysis platform to e-valuate the risking zoning of geological disasters in Hanzhong city.The results show that:(1)according to in-formation value and superposition analysis,the fault structure is the main controlling factor that induces geo-logical disasters,and geological disasters are highly prone to occur in areas adjacent to rivers or roads.(2)the extremely high and high risk areas in the study area,accounting for about 39.34%of the total area,was con-centrated in the central part of the study area;the medium-risk areas moderated risk areas are relatively scat-tered,characterized by the distribution characteristic of"Large dispersion and small concentration"and the relative concentrated district was mainly distributed in Hanzhong Basin;the extremely low and low risk areas in the study area,accounting for about 35.26%of the total area,was concentrated in the northern part and southern part of the study area.
geological disasterrisk assessmentinformation modelanalytic hierarchy processprin-cipal components analysisHanzhong city
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