基于变权TOPSIS模型的三峡库区土地生态安全评估——以巫山县为例

Evaluation of Land Eco-Security in the Three Gorges Reservoir Region Based on the Variable Weight TOPSIS Model——A Case Study of Wushan

为科学诊断三峡库区土地生态安全状况,弥补常规评估方法缺陷,本研究综合运用"惩罚型变权"理论、TOPSIS分析、层次分析等方法,构建变权TOPSIS复合评估模型,并从土地自然生态安全、经济生态安全和社会生态安全3个维度选取16项指标,构建三峡库区土地生态安全评估指标体系,对巫山县土地生态安全进行动态评估.实证结果显示,2003至2011年巫山县土地生态安全指数呈频繁波动、阶段上升趋势,土地生态安全变化大致经历中等水平(2003年-2005年)、低等水平(2006年-2008年)和高等水平(2009年-2011年)3个阶段,森林覆盖率低等问题得到缓解,但水土流失、地质灾害等依然严重,人口超载等开始显现.研究结果表明,变权TOPSIS复合模型能客观反映巫山县土地生态安全动态变化状况,满足三峡库区土地生态安全评估系统性、动态性需求.

In order to scientifically diagnose the situation of land ecological security in the Three Gorges Reservoir region, this study integrates the theory of punishment variable weights, TOPSIS （technique for order preference by similarity to ideal solution） analysis and analytic hierarchy analysis and, thus, constructs a composite variable weight TOPSIS model. Then 16 indexes are selected from the three dimensions of natural, economic and social eco-securities to build an index system for the dynamic evaluation of the land ecological security of Wushan county in the region. An empirical study shows that in the period from 2003 to 2011, frequent fluctuations occurred in land ecological security index in Wushan and exhibited a rising trend on the whole. The local land ecological security was at middle, low and high level in 2003- 2005, 2006-2008 and 2009-2011, respectively. In conclusion, the composite variable weight TOPSIS model can objectively reflect the land ecological security condition of Wushan and meet the requirements of land ecological security evaluation of the Three Gorges Reservoir Area.