基于物元模型的民勤绿洲土地生态安全评价

针对生态脆弱区民勤绿洲土地与生态环境系统的特点,运用“经济-环境-社会”模式和层次分析法构建了该区域土地生态安全评价的指标体系和权重,基于物元理论建立了土地生态安全的复合物元模型,对民勤绿洲土地生态安全进行了研究。结果表明:①2005-2007年民勤绿洲土地生态安全整体上呈现出“不安全-较不安全”的上升趋势,并有向更好等级发展的动向,说明近年民勤绿洲环境保护投入和治理绩效明显。②各单项指标存在明显的分异。人均水资源、化肥施用量、森林覆盖率、荒漠化程度、工业废水排放达标率、贫困人口比例和能耗成为制约该区域土地生态安全水平提升的重要因素,也反映了该区域土地生态系统环境容量低,极其脆弱。

Evaluation of Land Eco-security in Minqin Oasis Based on Matter Element Model Element Model

The Minqin Oasis is an ecologically fragile area in Gansu Province. Based on the characteristics of land resource and eco-system, this paper constructed a land eco-security evaluation index system and the corresponding weight values by applying the "economy-environment-society" model and analytic hierarchy process method, and then established a compound matter element model with the matter element theory to evaluate land eco-security of Minqin Oasis. Results showed that the land eco-security in Minqin Oasis improved slightly from insecurity to relative insecurity during 2005-2007, and this improvement resulted from environmental protection and management. There was significant difference among land eco-security evaluation results based on different evaluation indices. The factors such as the low water resource per capita, low consumption amount of fertilizer, low forest coverage rate, high desertification degree, low percentage of industrial waste water reaching standard discharge, high percentage of poor people and the high energy consumption per 10 000 Yuan GDP all hindered the improvement of the land eco-security in this area, which also indicated that the environmental capacity was low and the eco-system was fragile in this area.