The Study To Ecological Vulnerability Assessment In Horqin Sand Land

Located in horqin sandy land in north China, east of farming-pastoral region ecological environment has typical vulnerability and sensitivity. Meanwhile, nearly a century because of human transition, resulting in the sand by increasing deterioration of the environment, vegetation degeneration, biodiversity decrease, land desertification is getting more and more serious. Conduct vulnerability in horqin sandy land ecological environment for comprehensive understanding timely evaluation, environmental conditions and rebuild restore sand ecological environment and promoting the sand resources, population and environment, coordinated and sustainable development of the important theoretical and practical significance. This research in the heart of families choose sand HouQi left as research object, by this flag 1989, 1995 and 2000 and 2007, the four periods of eco-environment, mainly used for assessment unit "model method", and combining the method of landscape ecology and AHP method, combination weighting, model method and the GIS methods of study area, nearly 20 years of ecological environmental vulnerability assessment, quantitatively. On this basis, this paper discusses the research area the reason for the variation of the ecological fragile degrees. Conclusions are as follows: 1. Consulted experts to determined the eco-environmental vulnerability evaluation index in Kezuohouqi, applied AHP method, combined with "sensitivity-pressure-resilience" model, built four levels of eco-environmental vulnerability evaluation index system in Kezuohouqi.2. In the evaluation process, determining the weight has very significant impact on evaluation results. For compensate for the subjective and objective weighting method inadequacies, combined subjective weighting method of the Delphi method and the objective weighting method of binding entropy value method. Calculated optimal portfolio with obtained e two weights and thus calculated the weight of each index value.3. Have done quantitative analysis to eco-environmental evolutional process in Kezuohouqi. Ecological vulnerability is increased between 1989 and 2000, and slightly descended to 2007. In the 20 years from 1989 to 2007, ecological sensitivity is gradually declining, ecological pressure is increasing, and ecological resilience did not change significantly. Ecological sensitivity weight decreased 46.2%, ecological pressure index ascended 40.29%, resilience index has little changes, increased 5.94%.4. After determined eco-environment evolution process in Kezuohouqi, analyzed the cause of main elements of which affect on eco-environment vulnerability in Kezuohouqi. Provided proposal for how control the main impact index of environmental vulnerability.