Study On Geological Disaster Risk Evaluation Of Hanyin County, Shaanxi Province

Hanyin is the part of Ankang that is the qinba area，and is the development of geologydisaster areas, The geological environment and the natural ecological environment is of thefragile, and the unreasonable human engineering activities, give rise to the geologicalenvironment very bad, and the time on the local people’s life and property safety also seriouseffects Geological hazard risk assessment is the basis of scientific deployment andimplementation of disaster reduction, disaster prevention work, before the disaster riskassessment is particularly important. Through the mathematical model and the evaluation ofcombining GIS，constantly used in every category of geological disasters.As the research object of this thesis in shaanxi hanyin，combining the geological disasterinvestigation and regionalization report of Hanyin county and the current details such a theinformation of geological disasters, describes the traits of the geological hazards, using theAHP and GIS to come true the area geological disaster risk evaluation, and it is concludedthat:Hanyin have landslide, collapse, debris flow three kinds of geological disaster, by theend of2013years, totaling261points of geological disaster, debris flow10points, collapse27points, landslide in224points. Through the geological disaster development characteristicsof geological hazard and its topography, rock and soil type, structure, the affect of water andis closely connected with engineering activities.The time use consistency density, the types of landforms, geological structure, rock andsoil type, precipitation and human engineering activities the six factors and so on to evaluate.According to the estimate index divisor of influence degree of the development ofgeological disasters. Using AHP to calculate each index divisor weight, then to layerproperties of each evaluation factor. Completing the geological disaster risk zoning of Hanyincounty by MapGIS spatial analysis function. The study area results of divided into high,medium and low three grades, high risk zone area of287square kilometers, the central area of684square kilometers, risk low risk area of394square kilometers, each of the total area21.03%,50.11%,28.86%of the county. Choosing populace density、the density of arable land,road density, GDP and the government’s emphasis on geological disaster degree of five factorsto evaluate,Using AHP method studed the geological disaster hazard-affected body to objectivequantitative, The study area results of divided into high, medium and low three gradesincluding high vulnerability area area of177square kilometers, vulnerability in the area of 676square kilometers, low vulnerability area of512square kilometers, each of the totalarea12.97%,49.52%,37.51%of the county. Through to the geological disaster risk andvulnerability superposition of Hanyin county. Finally the results of geological disastercomprehensive risk zoning map to evaluation. The results are divided into three kinds of riskarea, the area of171square kilometers551square kilometers, respectively643squarekilometers, respectively, each of the total area12.53%,40.37%,47.10%of the county.Based on the results of geological disaster risk zoning of Hanyin county. The first of all，needing our country and local governments actively into the disaster prevention andmitigation，by improving the ecological balance, combining with the engineering andnon-engineering measures, make the problems of generated becoming little by little bygeological disasters.