基于P—S—R模型的陕西省土地资源生态安全动态评价

【目的】利用压力-状态-响应（P—S—R）模型对陕西省土地资源生态安全进行动态评价，以期为陕西省土地资源的可持续利用提供科学参考。【方法】基于P—S—R模型，以国家土地资源安全评价应用性评估指标体系为基础，结合研究区域土地资源生态特点，构建陕西省土地资源生态安全评价指标体系；并以1997～2006年陕西省土地资源数据为例，对其土地资源生态安全的变化进行定量评价。【结果】1996～2006年，陕西省土地资源生态安全系统压力指数整体上呈减小趋势；土地资源状态系统安全指数波动显著；土地生态安全响应指数呈明显增长趋势；土地生态安全综合指数变化可分为两个阶段：第一阶段（1996～1999年），土地资源生态安全综合指数波动明显，但总体上呈下降趋势，安全等级由临界安全转为较不安全，第二阶段（1999～2006年），土地资源生态安全综合指数逐年上升，安全状态也由较不安全升至临界安全。【建议】应继续坚持控制人口数量、提高人口素质的政策，坚持退耕还林为主的生态环境建设，推进清洁生产和循环经济，控制建设用地规模，从根本上降低区域土地资源生态压力，维护区域土地资源的生态安全。

Dynamic evaluation of ecological Security of land resources in Shaanxi Province based on pressure-state-response model

Objective]The pressure-state-response model has been used to evaluate the ecological security of land resources in order to sustainably use land resources in Shaanxi Province. Method]According to the ecological characteristics of land resources in Shaanxi Province, the index system for evaluating ecological security of land resources was developed based on pressure-state-response model and national index system of ecological security of land resources. On the basis of the developed index system, a quantitative evaluation was performed to evaluate ecological security of land resources using the data of land resources of Shaanxi Province from 1997-2006. Result]The results showed an overall decreasing trend of pressure index of ecological security of land resources from 1996-2006. The ecological security index （ESI） of land resources showed significant fluctuation and their response index increased significantly. From 1996 to 2006, the changes in comprehensive ESI of land resources in Shaanxi Province can be divided into two stages. During the first stage （1996-1999）, the comprehensive ESI fluctuated significantly, but showed an overall decreasing trend. The ecological security state of land resources changed from criticality safe to less safe. During the second stage （1999-2006）, the comprehensive ESI of land resources increased from year to year and the ecological security state changed from less safe to criticality safe. Suggestion]To reduce the pressure on the land resources and to enhance the ecological security of land resources, there is need to be adhere to the family-planning policy of controlling population size and to improve the quality of existing population, preserving ecological environment by making projects for reforestation on the farmlands, environmentally safe agri-produetion, recycling of agro-forestry materials and control of land construction size would be helpful in ways to the ecological security.