基于熵权可拓物元模型的耕地生态安全评价

Evaluation on Cultivated Land Ecological Security Based on Entropy-weighted Extension Matter-element Model

耕地生态安全评价是改善耕地生态系统状况,促进耕地可持续利用的重要基础。在界定耕地生态安全内涵的基础上,构建了基于"压力—状态—响应"(PSR)概念模型的评价指标体系,建立了熵权可拓物元模型,并以四川省为例进行了实证分析。结果表明:(1)2000—2008年四川省耕地生态安全水平呈逐步改善态势,但2008年"较安全"等级关联度很弱;(2)单位耕地农药负荷、单位耕地化肥负荷、人均耕地面积、土地垦殖率、水土流失程度等是耕地生态安全等级提升的关键制约因素。因此,为了促进耕地生态安全等级不断提升,需要进一步转变经济发展方式,降低经济增长对土地资源的过度消耗;大力发展绿色农业,合理施用农药、化肥;加大环境治理力度,有效控制水土流失。

Evaluation on cultivated land ecological security is of greatly importance in improving cultivated land ecosystem and sustainable cultivated land use. On the basis of defining the meaning for cultivated land ecological security, the evaluation index system was established based on the pressure--state--response （PSR） model. And then an empirical analysis was conducted in Sichuan Province by entropy-weighted exten- sion matter-element model. The results showed that： （1） The level of cultivated land ecological security had been gradually improved in Sichuan Province during the period from 2000 to 2008, but the coefficient of the correlation for the assessed rank of safer class was very weak in 2008~ （2） The factors such as, the pesticide load per unit of cultivated land, fertilizer load per unit of cultivated land, per capita cultivated land, land reclamation rate and extent of soil erosion were indentified as the key constraints for further improvement. Therefore, to improve the ecological security in cultivated land, economic development mode needs to be further transformed, excessive consumption of land resources need to be reduced, green agriculture need to be developed, pesticides and fertilizers need to be applied in a rational way, and environment and soil erosion need to be conserved effectively.