基于熵值法和灰色预测模型的土地生态系统健康评价

在界定土地生态系统健康内涵的基础上,构建了基于"压力-状态-响应"(PSR)模型的评价指标体系,采用熵值法和灰色预测模型,对四川省土地生态系统健康状况进行了评价。研究结果表明:(1) 1999-2010年四川省土地生态系统健康水平总体不断提高,综合指数从0.481 3增加到0.637 2,健康等级经历了"临界状态-亚健康"的演变过程;(2) 压力指数和状态指数总体上呈现下降趋势,响应指数总体上呈现上升趋势;(3) 人均耕地面积、土地垦殖率、水土流失程度、单位耕地化肥负荷、单位耕地农药负荷等是土地生态系统健康等级提升的关键制约因素;(4) 2011-2015年四川省土地生态系统健康水平呈现稳步上升趋势,年均增长率为2.86%。

Evaluation of Land Ecosystem Health Based on Entropy Method and Grey Prediction Model

On the basis of defining the meaning of land ecosystem health, the evaluation index system for land ecosystem health was constructed based on the PSR(press-state-response)model, then an empirical analysis was conducted in Sichuan Province by entropy method and grey prediction model. The results showed that:(1) The level of land ecosystem health had been gradually improved in Sichuan Province from 1999 to 2010, with the index increasing from 0.481 3 to 0.637 2. The degree of land ecosystem health generally experienced two stages, i.e., critical state and sub-health.(2) The pressure index and status index showed a downward trend, while response index, a rising trend.(3) The cultivated land per capita, land reclamation rate, extent of soil erosion, the pesticide load and fertilizer load per unit of cultivated land were verified to be the key constraints for further improvement of land ecosystem health.(4) The level of land ecosystem health showed a steady upward trend in Sichuan Province from 2011 to 2015, and the average annual growth rate reached 2.86%.