嘉峪关市土地生态安全动态评价及影响因素分析

土地生态安全评价对管控区域生态风险和保障生态安全具有重要意义.基于"数量安全-质量安全-结构安全-保障安全"模型构建指标评价体系,采用相对熵方法进行组合赋权,揭示嘉峪关市土地生态安全的动态变化过程,并运用因子分析法探讨其主要影响因素.结果 表明:(1)2000—2017年,嘉峪关市土地生态安全综合指数呈上升趋势,由20...

Dynamic evaluation and influencing factors of land ecological security in Jiayuguan City

Land is the basis of human existence and development.In recent years,the development of industrialization and urbanization has been accelerating,impact of human beings on the ecological environment has been increasing,and land ecological security issues such as structural contradictions in land use and land degradation have been gaining attention.These changes seriously restrict the sustainable development of society.The assessment of land ecological security is of great significance for the management of regional ecological risks and guaranteeing ecological security.In this study,Jiayuguan City of Gansu Province,China is selected as the study area and an index evaluation system is constructed based on the model of the“quantity safety-quality safety-structure safety-guarantee safety”framework.This study reveals the dynamic change process of land ecological security from 2000 to 2017 and discusses its main influencing factors using the factor analysis method.The results show as follows:(1)the comprehensive index of land ecological security increased from 0.415 in 2000 to 0.644 in 2017 and the level of security upgraded from being less secure to critical secure.However,the level of security is still low and the risk of land ecological security still exists.(2)In the subsystem,the quantity safety index fluctuated from 0.11 to 0.14,and its improvement effect was not obvious.The quality safety index showed an upward trend with a fast annual growth rate of 6.89%.The structure safety index increased from 2000 to 2009;its annual growth rate was 4.49%,and it fluctuated from 0.14 to 0.15 after 2009.The guarantee safety index showed an obvious fluctuant trend,exhibiting a rising trend in 2000-2004 and 2011-2017 and a declining trend in 2005-2010.The trend exhibited an inclined“N”pattern.(3)The main factors influencing the change in land ecological security can be divided into four aspects:the background of the resources and environment,succession of industrial structure,control of environmental pollution,and effect of ecological construction.These factors are of paramount importance for ensuring sustainable land use and ecological civilization in Jiayuguan City in the future.