The Study Of Eco-environmental Sensitivity Based On Grid Cell And Gray Clustering Method

With the increasing of human population,the social and economic development and the resources are exploited and utilized unreasonably, the eco-environmental problems such as soil erosion,soil salinization,biodiversity decreasing,greenhouse effect,acid rain and so on are appeared, The ability to resist outside interference of eco-environmental was weaker. The study is established in research of eco-environmental sensitivity which is a important aspect of eco-environmental research, it analyzes the factors that affect the eco-environmental and explores the technical methods of quantitative study of eco-environmental, has important theoretical and practical significance.In this study, space grid was taken as the evaluation unit and the eco-environmental sensitivity evaluation index system was established from the natural factors and human disturbance factors, gray clustering method was adopted to evaluate the eco-environmental sensitivity. In view of the difficult problem that how to achieve gray clustering model in GIS based on grid cell, the new method "decomposition-Synthesis" was first proposed and it hoped that it could provide a new evaluation method for eco-environmental sensitivity study. This study has achieved the following results: (1) The study of the evaluation index system:combining the actual situation of the eco-environmental sensitivity in study area,the eco-environmental sensitivity evaluation index system was established from the natural factors and human disturbance factors which include 4 integrated indicators:soil erosion sensitivity,habitat sensitivity,soil salinization sensitivity and human disturbance sensitivity, and 13 basic indicators such as R-value,terrain roughness,soil texture and so on.(2) The use of GIS and RS technology:For the index system above, RS used to obtain land use and vegetation cover information; terrain slope,soil erosion,dryness and socio-economic factors such as traffic and population are analyzed and treated by GIS technology.(3) Evaluation units are grid:In this study,Orthogonal linear divided study area into many rectangular grids as evaluation units; The "grid focus method" based on density principle has achieved grid expression of socio-economic indicators such traffic and population, it's overcomed defects which take administrative as evaluation unit in previous studies.(4) The set up of evaluation model and innovation of technical methods: The study uses AHP to determine the weight of each index, and divided sensitivity level for 4 integration indicators by gray clustering method, it has set up of gray clustering model for eco-environmental sensitivity evaluation, and the new method "decomposition-Synthesis" was first proposed which combine gray clustering model whit GIS technology based on grid cell,this Solve the problem of non-ultra-high column of gray clustering matrix operation.(5) The model verification:The study take Hunyuan county of Shanxi as an example, carried out empirical study on gray clustering model,the evaluation results basically accords with real situation of eco-environmental of Hunyuan county. and have proved the model is correct, feasible and workable...