Researches On Ecological Security Evaluation And Spatio-temporal Variation Characteristic Of Cultivated Land In Hubei Province

Cultivated land is the material basis of human survival and also the essence of land resources. The ecological security of the cultivated land is important to guarantee the food、economic and social security. The amount of cultivated land resource is reducing and the quality of cultivated land is also descending because of the industrialization and urbanization process, a large number of the fertilizers and pesticides also cause the soil pollution, and make the ecological environment worsening. The ecological security of cultivated land is facing increasingly severe challenges, and it has a threat to the sustainable development of agriculture and social economy. This paper takes cultivated land resource in Hubei province as the research object, based on the DPSIR model to build index system.It uses Analytic Hierarchy Process (AHP) and entropy weight method to determine index weight to evaluate the situation of ecological security of the cultivated land resource in17cities of Hubei province. Based on the evaluation results, it makes analysis in time and space. Finally, it has the following conclusions:(1) The ecological security situation of the cultivated land in Hubei province is in form of general positive changes. The evolution can be roughly divided into two stages. First is the risk-sensitive stage in2002-2006.In this stage, the ecological security level of the cultivated land is low, the state index and response index reaches the lowest in2003.Second is the critical safety-safer stage in2007-2011.In this stage, the ecological security level of cultivated land is in critical-safe status in2007and2009because of the fluctuation of the driving force index.(2) The changing trends of ecological security in17cities are in accordance with the Hubei province. Most of the cities transfer from sensitive state to critical-safety state in2003-2005, and from critical-security state to the critical-safety state in2007and2009. Most of the cities moved into a safe condition in2011.(3) Using the time series analysis method to analysis the ecological security index of the cultivated land. It reflects that the driving force index, effect index and response index are rising, only the pressure index is falling in2002-2011.Those indexes are mainly affected by chemical fertilizers, pesticides, and agricultural films.(4) Using the spatial autocorrelation analysis method to analysis the spatial distribution of cultivated land ecological security status in Hubei province. It refle cts that "Wuhan-Ezhou-Huangshi" area and "Enshi-Yichang-Jingmen-Tianmen" area have a negative correlation, and account for about40%area of the map in Hubei province."Jingzhou-Qianjiang-Xiantao-Xianning" area and "Shennongjia-Shiya n-Xiangyang-Suizhou-Xiaogan-Huanggang" area has a positive correlation, and acco unt for about60%area of the map in Hubei province.