重庆市土地生态安全动态变化研究

Evaluation on Land Resources Ecological Security Trends of Chongqing Municipality

土地生态安全评价是土地资源可持续利用研究的前沿课题.以重庆市为例,从自然、经济、社会3个方面建立了土地生态安全评价指标体系,以熵权法确定指标权重,运用土地生态安全综合模型计算了2002-2011年的土地生态安全综合指数,并分析了土地生态安全协调度的动态变化.结果发现:1)2002-2011年重庆市土地生态安全状况经历了从恶劣级、风险级、敏感级到良好级的转变,土地生态安全在波动中呈现转好趋势.2)土地生态安全协调度总体呈下降趋势,土地生态系统安全的良好状态有待于进一步巩固.其中,2002-2004年土地生态安全水平处于恶劣级,系统内部虽较为协调,其本质却是一种不良的反映;2005年虽处于恶劣级,但系统协调度大幅下降,处于不协调状态;2006-2009年土地生态安全转好,处于风险级,系统处于协调状态,这为土地生态状况转好提供了保障;2010-2011年土地生态安全由敏感级上升到良好级,系统协调度下降明显,不过与恶劣级的协调本质不同的是,这是一种良性的转机.研究认为,构建土地生态安全评价指标体系,并引入土地生态安全综合计算模型和协调度模型,对监督土地生态安全状况具有较强的科学性和实用性.

Evaluation on land resources ecological security is a forefront research topic of sustainable utiliza ‐tion of land resources .Taking Chongqing as an example ,an index system on ecological security of land re‐sources ,including natural ,economic and social aspects ,has been established .The paper determines the index weights in entropy value method ,calculates composite index of land resources ecological security with comprehensive model of land resources ecological security and analyzes the dynamic changes in coordi ‐nation degree of land ecological system .Results show ：First ,during 2002 - 2011land ecological security situation in Chongqing experiences a change that it rises from harsh stage ,risky stage ,sensitive stage to performing safety stage .Land ecological security shows a trend of improvement in the fluctuation .Sec‐ond ,the coordination degree of land ecological security in general is on the decline .Land ecological securi‐ty situation is not stable and needs to be further consolidated .Land resources ecological safety is at harsh stage during 2002 - 2004 ,although system is coordinated but in a bad state of coordination .It is still at harsh stage in 2005 while coordination degree has dropped significantly and system is uncoordinated .It is growing better and at risky stage during 2006 - 2009 .At the same time system is coordinated ,which pro‐vides guarantee for better ecological safety .From 2009 - 2011 land resources ecological security rises from sensitive stage to performing safety stage .Coordination degree decreases significantly ,which is different from coordination of harsh stage essentially and turning better .Research suggests building evaluation in‐dex system on land resources ecological security and introducing integrated computation on land resources ecological security and coordination degree models ,which has strong scientific and practical significance on supervising situation of land resources ecological security .