Space Change Of County Land Ecological Security Based On PSR Model

In recent years, with increasing human land use activities, land ecological andenvironmental problems become increasingly prominent, which threat the landecological security. As an important aspect of ecological security, ecological securityof land related to the sustainable use of land resources, and land ecological securityevaluation research helps people understand the land ecological security state to takeeffective measures to protect the land ecological security and maintain the sustainableuse of land resources.In this study, we take Wu’ an city as an example and establish evaluation indexsystem of land ecological security using AHP and based on the "pressure-state-response" model (PSR model), and integrated "social-economic-natural" model. The overall goal of the evaluation index system is land ecological security evaluation.Under the overall goal sets three subsystems of pressure, state and response. Continuedown sets socio-economic and natural two elements layer. And considering dataaccessibility we selected26representative evaluation indexes. With the establishedPSR evaluation model, we evaluate the spatial and temporal dynamics of landecological security in Wu’ an city. In time perspective, we evaluate land ecologicalsecurity in times from2001to2010, and analyze the development and changessituation of land ecological security state in10years in Wu’ an city. In spaceperspective, we evaluate land ecological security of each village and each town in Wu’an city in year of2005,2009and2010, and analyze the difference and developmentof each village (town). Finally, combining with the study results, we presentedcountermeasures and suggestions to help improve the state of land ecological securityand safeguard the sustainable use of land resources in Wu’ an city.The main conclusions of this study are as followings:(1)In time scale, from year2001to year2010, the integrated value of land ecologicalsecurity in Wu’ an city improves gradually, and land ecological security situation isgradually improving. In2001-2005, the land ecological security is in grade Ⅲwhichrepresents general security status. Beginning in2006, the land ecological security level is one level raise, and changes to grade Ⅳsafer state.(2)In space scale,2005-2010, the integrated value of land ecological security in22villages (towns) in Wu’ an city keeps improving, but the changes of landecological security status are quite different in the township’s. The number of townswhose land ecological security level raises is10, and the number of towns whose landecological security situation changes to grade Ⅲ general safety from grade Ⅱ lessinsafety is5,besides, the number of towns whose land ecological security situationchanges to grade Ⅳ less safety from grade Ⅲ general safety is5. During the studyperiod, the towns whose land ecological security ranked quite early are Guan Tao andHuo shui, while the towns whose land ecological security are after ranking bycomparison are Shu cun and Shang tuan cheng.(3) We put forward targeted suggestions against Wu’ an’ s current land ecologicalsecurity status and major land ecological security problems, in order to improve thelocal ecological security of land, and promote rational and efficient use of landresources and sustainable development.