Assessment On Agricultural Ecological Security In Dunhuang Oasis

In recent decades, ecological environment overall showed a deterioration tendency as the global human-land conflict became more acute. It mainly presented as aggravation of land degradation,imbalance of ecology,destruction of vegetation,reduction of biodiversity etc, human are facing with new threats constantly. Not only the security of national defense,politics and economy but ecological deterioration have impact on national security. Therefore,the definition of national security is extended successively and the conception of ecological security,environmental security and resource security are put forward by scholars home and abroad. Ecological security problems play a vital part in geography,resource and environmental science and ecology.Researches on sustainable development of agriculture have received the general concern of the international community recently,and the agricultural ecological security is the forefront. The study on the evolution of ecological security of agricultural sustainable development with a deep understanding of the extent and causes of agricultural ecological environment has theoretical and practical significance in guiding the construction of agricultural ecological environment and realize sustainable development of agriculture.Dunhuang Oasis locates in the east of Gansu province,It is situated in the interchange of Gansu, Qinghai and Xinjiang provinces, an important part of Hexi Corridor oasis. It is a typical eco-environmental fragile area because of drought,shortage of water resources,sparse vegetation,frequent natural disasters and serious eco-environmental degradation. The sustainable development of agricultural becomes more and more serious as the rapid development of agricultural economy in recent Abased on the pressure-state-response(P-S-R) model which formulated by The United Nations Environment Programme(UNEP)and previous researches and quantitatively evaluate the ecological security of agricultural sustainable development by using ecological security evaluation model with a view to provide a scientific guidance for sustainable agriculture and ecological security in Dunhuang oasis.The paper includes the following six parts:First of all, clear out the conception of ecological security,connotations and background, describe the subject selection background and research progress at home and abroad .And then discuss the purpose,significance and theoretical basis and methods.The second part , gives an analysis of agricultural systems of the Dunhuang oasis. A comprehensive exposition of the development status quo of agriculture in Dunhuang oasis is presented based on an overview of the natural and socio-economic situation at first and then we analyze the existed issues of agricultural systems with the combination of the existing data.In the third part,Continuous data between 1981 and 2005 are applied with P-S-R model on the basis of understanding the designing principles and concept of ecological security index system. The indexes are selected from three aspects which include the pressure, quality and capacity of construction of ecological environmentalIn the fourth part,entropy method which is an objective method is used to determine the weight of index system. Utilizing Multi-level and multi-objective fuzzy optimization model to calculate the comprehensive values.Analyze the evaluation results on the basis of the comprehensive values.Part five puts forward development countermeasures for ecological agriculture in Dunhuang oasis. The measures are based upon a deeper understanding of ecological security status of agriculture and the results of the ecological security evaluation analysis in Dunhuang oasis.A conclusion and the direction of further study in view of the inadequacy are proposed at the end of the text.