| In recent years, with the advance of western development, various human activities ongeological engineering increasingly serious environmental damage, accompanied by theflow of a large number of landslides and other geological disasters occur, and as thewestern Qinba Mountain has special geological environment and regional socialenvironment, it is the hardest hit of geological disasters. Explore a scientific assessmentmethods in disaster prevention and mitigation of disaster prevention and rescue Qinlingregion respect for local government organizations is significant. In this paper, XunYangexample, relying Shanxi Institute of Geological Survey commissioned "XunYang detailedinvestigation of geological disasters" project, on the basis of XunYang field investigationand laboratory data collated on a detailed analysis of geological disasters in the study areadevelopmental type, distribution, growth conditions and factors, and then combined withGIS technology, through the AHP and the amount of information law finally get pronezoning. Specific contents of this paper are as follows:(1) through geological disasters XunYang field survey and data collection, combinedwith Arcgis layer analysis, summarized XunYang type and distribution of geologicaldisasters: a major geological disasters as landslides in the study area, accounting for91.4%of the total, followed by avalanches, landslides, ground subsidence; spatial distribution ofgeological disasters in the study area law:①major rivers and river valleys density area,②five fault zone near,③strong areas of human activity, such as316State Road,Highway201, Xiangyu, ten-speed road network, such as roads and densely populated areason both sides of the river, construction, roads surrounding the disaster showed a bandedlinear distribution; time distribution is:7,8,9months every year is a major geologicaldisasters several months.(2) The study area and close to the base of geological disasters factors andpredisposing factors are: engineering geological rock group, aspect, slope, slope elevation,slope shape, annual rainfall, fault, rivers, and the nearby road and rail. (3) In prone evaluation methods, the paper uses two methods of AHP and the amountof information law, the qualitative analysis into quantitative analysis, combined with GIStechnology, get zoning prone to two different methods. Both methods in determining theevaluation factors based on the following steps: AHP first established evaluation system,and then combined expertise and weighting formula to get the weight value of each factor,followed by an assignment to various factors, combined with GIS technology has beenevaluated factor normalized one of the maps, Finally prone index formula andreclassification of GIS functions are prone zoning study area; information method toevaluate factors selected layers reclassification, after the use of GIS functionality combinedwith single factor information for money and information on the magnitude of the totalcalculated values were obtained for each factor information and total information value, thefinal total is divided by the uniform equidistant magnitude of information obtained in thestudy area prone zoning map. Papers obtained by the two methods will be prone to getzoning diagram comparing the integration of Xunyang susceptibility zoning map. Pronezoning study area prone to high, medium-prone, low-prone, the results were as follows:High-prone total area is1650.944km2, mainly in the Han River, late River severalmajor rivers, roads on both sides, representing46.59%of the county area; prone total areais1740.519km2, accounting for49.12percent of the county area; Low-prone area is151.826km2, mainly in the northern mountainous area, accounting for4.28percent of thecounty area.(4) By comparing the two evaluation methods found differences between them and thepros and cons, the same point: two evaluation methods for each level of disaster pronedensity and total disaster prone density ratio as equivalent increases, indicating that the twomethods are in good agreement with the actual situation; different points: AHP and theamount of information laws exist different algorithms, different factors deal with differentdegree of quantification, and the amount of information law in disaster-prone areas of highpoints in the ratio of AHP more comparison, the amount of information law is moreaccurate. Evaluation of the former is pure quantitative analysis, which combines the expertise affected by human factors. |
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