Abstract:

As the goal of completely building a moderately prosperous society was raised in the report of 18th CPC National Congress,the development of society and economy in China would be further accelerated and the pressure on the environment was bound to increase as well.Ecological safety has become a very important part of national security and social stability.How to coordinate urban development and urban ecological safety has become a unavoidable problem.Moreover,China is a mountainous country in which mountainous region accounts for 69% of the land area.In the hilly areafragile mountain ecosystems,frequent natural disasters and serious soil erosion have restricted the social and economic development.Exploratory research on ecological safety had been done by some scholars.Currently,researchers mainly used comprehensive evaluation method,analytic hierarchy process evaluation method,the fuzzy matterelement method and the ecological footprint method to do the ecological safety evaluation.However,due to the differences inherent in the selection of ecological safety indices as well as each kind of methods,this article used the PressStateResponse framework model and gray system theory to assess ecological safety indices.In order to provide a scientific basis for decision making for the coordinated development of the socioeconomy and environment in Wushan County,the study combined the entropy weight method and gray system theory to analyze statistics of various indices of Wushan County from 2001 to 2011.The gray correlation analysis is a method which is a quantitative description and comparison of the development and changing situation of a system.The basic idea is to determine the degrees of geometric similarity between the referential data columns and a number of comparative data columns to decide whether they were closely linked,so that the magnitude relation between the various subsystems can be calculated.The research used the entropy method to assign weights to various indices, and calculated gray correlation degrees of each indices which had been reflecting the ecological safety state of Wushan County,and then evaluated the situation of ecological safety level of Wushan County in 3 aspects of press,state and response.It was the first attempt that entropy empowerment and gray correlation analysis were combined and applied to the field of ecological evaluation in the mountain city.Relative to other methods,entropy empowerment was more objective and avoided other interference.So that the results of the evaluation would better reflect the actual situation of the study area.The procedure for calculation was presented in detail.On the basis of the computing results,the ecological safety index of Wushan County from 2001 to 2011 was developed from 059 (level Ⅲ) to 0.66 (level Ⅳ).The ecological safety indices values during these years had fluctuations,and the overall ecological safety conditions showed a good momentum of development,as a result the environmental pressures was eased in some degree.But the ecological security indices and its subindices are still in a high level.Moreover,most of the time the rise was not obvious,and ecological safety composite index was hovering around 06.The environment was in a safe state