陕西省土地生态安全动态评价及障碍因子诊断

研究目的:通过构建土地生态安全评价指标体系,对2001—2012年陕西省土地生态安全做出动态评价,并诊断出主要限制性因子。研究方法:运用基于相对熵理论的组合赋权法确定权重,采用综合指数法进行评价,最后通过障碍度模型找出土地生态安全的限制性因子。研究结果:(1)12年来陕西省土地生态安全指数逐渐上升,安全级别由临界安全提高到较安全等级,但目前土地生态安全水平属于低层次、不稳定的较安全等级,土地生态安全压力还很大。(2)从准则层看,土地生态安全的主要威胁仍来自质量安全和安全保障两方面,其中土地退化的障碍度越来越大;从指标层看,最大障碍因子经历了由单位面积农林牧副渔产值、水土流失率到土地沙化率的变化。研究结论:基于相对熵权的土地生态安全动态研究结果符合陕西省实际。

Dynamic Evaluation and Diagnosis of Obstacle Factors on Land Eco-security in Shaanxi Province

The purpose of this study is to evaluate land eco-security and diagnose its main stumbling factors in Shaanxi Province from 2001 to 2012 through establishing land eco-security evaluation index system. Methods include combination-weighting method based on relative entropy theory and comprehensive index method. Also the stumbling degree model was used to find the limiting factors of the land eco-security. Results show that 1） the land eco-security value of Shaanxi Province has gradually been increasing for 12 years, and the grade of land eco-security has changed from critical security up to general security. At present, the land eco-security was in low and unstable general security condition, so pressure of land eco-security was still very great. 2） In the criteria layer, the main threat to the land eco-security still came from quality security and safety assurance, including the land degradation stumbling degree increasing; from the perspective of index layer, the first stumbling factor changed from output value of agriculture, forestry, animal husbandry and fishery per unit area, soil erosion rate to land desertification rate. It is concluded that the results of land eco-security dynamics research based on the relative entropy accord with the actual situation of Shaanxi Province.