Comparative Study On Application Of Environmental Vulnerability Assessment Model In Karst Mountain System

The human survival and development of the indispensable external conditions is that of the environment, however, humans have always plundered and destroyed, resulting in their own environmental conditions around is facing an unprecedented challenge. This challenge of performance is particularly prominent in the developing countries.50’s and 60’s of the last century, human beings have gradually realized that environmental protection and economic development are equally important. And sometimes the former is at a more important position than the latter. For environmental vulnerability study also begins at this time, then study on environmental vulnerability assessment has gradually expanded and deepened. Karst mountain area of system in the South-East of Yunnan province is one of the more typical eco-environmental fragile area in China. Many problems in this area is prominent, such as karst rocky desertification problem is serious, the natural vegetation cover reduced, serious soil erosion, the quality of the land is barren as well as the people lives in poverty and so on. In recent years, there are many models and methods of evaluating the vulnerability of mountain sys+tem in karst environment, but most researchers are in a set, they do not contrast and research the assessment models or methods. This paper contrasted many evaluation model and method of and selected three kinds of models, in addition, it assesses environmental vulnerability in study area of Yanshan County, southeastern Yunnan province in Central region. This paper hope that through the application of the model, the one, it can obtain thevulnerability environment present situation of the karst mountainous region in research area, with the help of the results of environmental vulnerability assessment compare and analyse the three models.The main research contents and results are as follows:(1) Through the detailed elaboration research background and the selected topic basis, the domestic and foreign research present situation, the research content and the research rationale and the technical method, complete the theory part for paper core content writing the upholstery work.(2) First of all, in the case of introduction of southeastern background of karst environment, selected typical as thesis research area, Yanshan County, and introduced the natural, social and economic conditions in the study area. Secondly, on the comprehensive analysis of karst mountain system environment vulnerability after driven mechanisms, the respectively selected from the two driving mechanisms of natural and anthropogenic factors 14 representative indicators to build environmental vulnerability in karst mountain system and assessment indexes system. Then using analytic hierarchy process (AHP) determined the weight value of these 14 indicators factor.(3) Using the village as a vulnerability assessment unit, the RS, GIS data and statistical techniques obtain the assessment indicators of the data, and build a vulnerability assessment database. By the comprehensive weighted index analysis model, the indicator index model and the principal components analysis model were separately carried out environmental vulnerability assessment, and each evaluation results are expressed, explained and demonstrated. Three types of evaluation results have shown that Eastern regions of fragile environment in the study area are better than others, Central and Northern regions of fragile environment are worse.(4) Between three kind of the comprehensive weighted index analysis model, the indicator index model and the principal components analysis model obtains makes the detailed contrast analysis. The results showed that the comprehensive weighted index analysis model and the indicator index model of environmental vulnerability results are similar. Principal component analysis model compared with the other two models, environmental vulnerability rating is lower as a whole. Further comparison of the comprehensive weighted index analysis model, the indicator index model and the principal components analysis model, detailed clear similarities and differences between models and their respective characteristics, provides the theory reference for the selected domain environment in karst mountain area after the vulnerability assessment model.