基于相图法的河北省农业生态经济系统可持续发展对策研究

Countermeasures of Sustainable Development for Agricultural Eco-Economic System in Hebei Province Based on Ternary Diagram

通过收集2001—2016年河北省农业生态经济系统各类资源投入数据,结合能值理论和三元相图法分析系统资源能值投入结构,对系统可持续发展现状进行评价,并对系统未来发展方向做出预测。结果表明,研究期间河北省农业生态经济系统能值投入中,可更新资源能值利用比例稳中有降,不可更新环境资源能值利用比例逐年下降,而社会经济系统反馈能值利用比例逐步升高,导致系统环境负载率、能值自给率逐年下降,即农业生态经济系统对环境的依赖程度减弱,对系统外部能值投入的依赖性增强。研究期间系统可持续性指数均小于1,并逐年降低,表明系统为消费型系统,且不可持续性逐年加强。因此,亟需调整农业生产投入结构,保持系统不可更新资源能值和反馈能值的比例基本稳定,增加可更新资源能值的投入,促进河北省农业生态经济系统健康可持续发展。

As a major agricultural province,Hebei provides an important guarantee of food security for Beijing-Tianjin-Hebei region.However,due to overexploitation of groundwater and excessive application of pesticide and chemical fertilizer,the agricultural production process in Hebei has caused a series of environmental problems,which in return restrain the system from sustainable development.Data of input resources were collected for Hebei Province′s agricultural eco-economic system during 2001-2016.Emergy theory and ternary diagram were combined to analyze resource allocation and its tendency of system input and optimize development path of the system.The results showed that the allocation of system input resources gradually changed.Specifically,the renewable emergy utilization ratio for the system gradually decreased and the rate of non-renewable environmental resource utilization also decreased,while the ratio of purchased non-renewable emergy input gradually increased.The changes in resource allocation indicated that the system became less dependent on the local environment,but the dependence of system on the external emergy input was gradually enhanced.Moreover,the increasing of emergy investment rate suggested that agricultural production process should consume more purchased emergy while using the same amount of local resources.The ratio of renewable resources to non-renewable resources kept as 1.71∶1 showed that the input of renewable resources was higher than that of non-renewable resources,indicating that Hebei Province has sound natural environment and climatic resources.However,the emergy sustainability index(ESI)values during the study period were lower than 1 with a yearly decrease,which means the system was not sustainable in the long run.According to system tendency analysis,comprehensive measures should be taken to keep stable the ratio of non-renewable resource emergy to purchased emergy and to increase the input of renewable resources in order to realize sustainable development of agricultural eco-economic system in Hebei Province.