A Research On Geological Disaster Risk Assessment And The Measure Of Prevention In Qingchuan County Of Sichuan Province

With the development of society and economy,human beings keep on expanding their living space to mountain areas.As a result,geological disaster occur more and more frequently in recent years.Qingchuan county often happens geological disaster, and because of this have caused very large loss of economy and riches,especially between 2005 and 2007,the right economic loss by geological disaster come to 103,81 million dollars.In order to find environment background what geological disaster happened are being and the causing toit,an effective geological disaster risk assessment needs being ensured to prevent hazards and reduce its economic loss,a complete model for hazards assessment also must be quickly searched for,In this paper,reasonable discussions have been dug into this research area,and major outcome has been obtained as follows:(1)Proposed the clear geological disaster risk assessment method mentality,also - obtains the result - result analysis from the preparatory stage - acquisition of information - material analysis - factor quantification - model evaluation,caused the crosswise material - longitudinal data,the open country foundation - indoor sublimation,the primary data - result model organically to unify,has completed the entire geological disaster risk appraisal system;(2)Has analyzed the regional geology environment background which carefully the geological disaster occurs,as well as with the geological environment related geology disaster spatial distribution,had determined the risk appraisal is pregnant the disaster environment factor;(3)Has analyzed the suggestion factor which carefully the geological disaster occurs,and the deep research occurs in recent years the geological disaster's suggestion factor with its disaster spatial distribution relations,withdraws the suggestion factor data which the geological disaster occurs;Pregnant the disaster environment factor and the suggestion factor characteristic is: physiognomy in Qingchuan County mainly is for etching structure middling mountain as well as for etching structure low mountain landform,slope majority between 15-30°; Each stratum becomes the banding type mop approximately along the structure alignment,Cambrian series Qiu Jiahe group,The fourth series the holocene deposition (the stratum code number separately as∈q,Qh I)distributes the stratum is broadest; In the area there are three different structure areas,north for assuming north east to Qiaozhuang big breaks,south for assuming north east toChaba big break,Qiaozhuang big breaks is high peak of Yangzi paraplatform,called Motianling;South of Chaba big break is Longmen Mountain - Daba Mountain pleat,which the Yangzi paraplatform breaks Longmen Mountain of pleat the belt to break ties,between two breaks is the Songpan - Ganzi geosyncline system of fold,the Longmen Mountain miogeosyncline belt of folded strata,the climate is wet differently,the structure activity is intense,is also.in the Longmen Mountain earthquake to take to bring with,the rainfall centralism, the rainfall is abundant,the rainfall mainly concentrates in July to September,these three month-long rainfall amount accounts for the annual rainfall amount above 50%, generally appears in early August or middle ten days' year maximum date rainfall amount is 80-100mm,the human project activity is intense;(4)Analyzes Qingchuan County typical disaster essential feature,the disaster factor,carries on the qualitative geological disaster risk appraisal,causes from the analysis angle to the.Qingchuan County geology disaster's growth characteristic deepening understanding,Also say that firstly the geological disaster environment is located,the disaster growth characteristic is descripted,then carrying on an environment origin analysis,judging whether to be at the critical condition,finally carrying on the risk appraisal and the prevention suggestion;(5)Proposed the regional geology disaster risk appraisal's realistic way,namely the appraisal may follow "the origin mechanism analysis -subregion division -sensitive factorial analysis and the qualitative analysis inference -mathematical model superimposition analysis - quality synthetic evaluation" this kind of flow,and has annotated this flow well with Arc view,has obtained the achievement chart,Also uses the sensitive factorial analysis to carry on the factor the quantification,utilizes mapgis and arc view software establishment appraisal factor graph database(1:100,000),the form expresses each factor attribute by the grid(388mx388m),altogether obtains 21712 unit cells,the extraction geology disaster locates the position various factors attribute data and indicated by the raster data,computating geology disaster and grid whose attribute relative frequency,and calculating every 100 square kilometer in disaster points quantity,finally obtain each factor attribute's class sensitivity,the lothological factor and the rainfall factor is the Qingchuan County geology disaster's high sensitive factor,in each appraisal factor graph database's foundation,the superposition analysis tool by using arc view,applying the multi-layered space digit chart level which the GIS analysis will establish to carry on the numerical and normalized processing,namely according to 1,2,3 and 4 values bestows on separately for each appraisal grid, classifying separately the above five sensitive factor's iteration synthesis value≤8,9～11, 12～15,≥16 as void,low,neutral and high warning area about limit value as the division, and obtains the Qingchuan County geology disaster risky evolution map;(6)In the risky regionalization result's foundation,proposes the prevention countermeasure,takes refuge from danger the relocation and the group for the geological disaster measured that the group against provides the basis,For example,the leading is giving way to traffic the relocation the policy,combine renovating and group preventing geological disaster,establishing the network system for group preventing geological disaster pertinencily,a typical disaster prevention should consider primarily the relocation the policy and renovating,then network system containing group preventing geological disaster need be setted up,in addition,human's activities must be paid attention to the geological disaster's suggestion function.