The Quantitative Research On The Danger Assessment Of Regional Geological Hazard

China is a country with a vast territory, abundant resource and longcivilized history. Thousands of anthropological activities, especially thehigh-speed development of economy and excessive increase of populationthese several ten years, aggravate the requirement of nature. Irrationalengineering of humankind is aggravating the danger of geological hazardsday by day. Defending and reducing disasters have become a very pressing,inevitable and realistic social problem. The world attaches much importanceto danger assessment of geological hazard, which is basic work to put thescientific management of geological environment into practice. The dangerassessment of geological hazard is not only the foundation of deep understandof endangered status but provide scientific gist to frame prevent and curemeasure in practice, to optimize and manage item and so on .Based on the things upwards, the article combine the work of geologicalhazard survey item "The Survey and Zoning of Geological Hazard in thePanshi city of Jilin province" issued by the Ministry of Land and ResourcesP.R.C, using the disaster and territorial geological environment datainvestigated on the spot, and apply two methods of fuzzy synthesizeassessment and grey clustering to the danger assessment of regionalgeological hazards, then discuss the rationality. The aim is to use the twomethods of fuzzy synthesize assessment and grey clustering on analyzing therisk of geological disaster to satisfied the requirement of facility, practicalityand rationality put forward by practice.First, the article introduces the general condition of the nature geography.Based on the inner discussion about the formation origin and mechanism ofthe disasters of falling, landslide and debris flow, it analyses the relationbetween the disasters and many kinds of controlling factors including natureconditions, geology background, climate condition, vegetation cover andhuman factors.Then after, the article applies the two methods of fuzzy synthesizeassessment and grey clustering, selecting important factors and establishingmathematical model to assess the risk of geological disaster. That can notonly prove each other, but also reflect the influence degree of different factors.That merges different units of the same danger into one. In order to evaluatequantitatively the risk of geological disaster, the whole area of Panshi city isdivided into 86 units.For too much factors, fuzzy synthesize assessment method selects thetwo-level model. The evaluation set has four-stage standard, that is to say thedangerous degree of the disaster is divided four stages. It selects four primaryfactors, including geological condition, topographical condition, climate andvegetation cover condition, and human condition. They include ninesecondary factors, which are lithologic characters, structure density,earthquake intensity, degree of slope, relative height difference, morphologictype, rainfall intensity, density of cover and human condition. Membershipfunction adopts the echelon form one. Fuzzy analytic hierarchy process(FAHP) is used to determine the weight of above factors. After fuzzymapping and comprehensive evaluating, the unit's risk degree is determined,according the principle of the maximum membership grade. The article takesthe 64th unit for example. Then all the units' risk degree are determined.In grey cluster analysis, the quality of Panshi's environment is qualitativeresearch system as a grey, and grey cluster method is used in the geologicaldisasters risk assessments. Nine assessment factors are selected , structuredensity, earthquake intensity, degree of slope, relative height difference,morphologic type, rainfall intensity, density of cover and anthropogeniccondition. The raw data of the various input data sample are different in sizeand dimension. In order to avoid the results of the evaluation by the impact ofthe difference, the average standardized method is used to process the rawdata before applying them.According to the classification standards of the risk assessment whitefunction is put forward. The weight of the evaluation factors are calculated byformulation. According to different geological units of Panshi city, whitfunctions of different affiliation grey category are set, and then the weightedclustering coefficients are calculated. According to the largest affiliation ofthe geological units geological disasters dangerous level is identified. Thearticle takes the 64th unit for example. Thereby the risk levels of all the unitsare determined.By comparing and analyzing the two evaluation methods, it can be thatthey both can reflect the risk degree of Panshi city, and get almost the sameassessment results. Because the types of indicators and evaluation indicatorshave some difference, there is slight difference in discrete unit. On thewhole, the assessment results coincide with the actual situation. According tothe results Panshi city is divided into four region with different risk degree.Applying two methods of fuzzy synthesize assessment and grey clusteringto the danger assessment of geological hazards in Panshi city, it getssatisfactory result. But when the two methods are applied, not all the factorscan be quantified, the paper put forward some advisable suggestions to theproblem.