基于灰水足迹的粮食主产区农业环境效率与水环境可持续性测度与评估

目的]为实现粮食主产区农业水环境的可持续发展。方法]文章应用灰水足迹理论,选取我国粮食主产区洞庭湖区34个县(市)为案例研究区,采用非期望产出的SBM窗式分析模型,系统解析农业环境效率的时空演变特征。通过构建农业资源节约与灰水足迹减排潜力、缩减规模和水环境压力降低潜势模型,进行农业环境效率与水环境可持续性测度与评估研究。结果](1) 1994—2014年水环境污染约束条件下洞庭湖区农业环境效率相对较低,总体呈波动增长的态势;21年来灰水足迹具有较高的减排潜力。(2)洞庭湖区农业环境效率分布呈较大的空间差异特征,高效率区主要集中于环洞庭湖区与远离湖区的南部地区;农业环境效率相对有效的地区呈逐渐增加的态势,且分布趋于均衡。(3)湘阴县与华容县农业生产的灰水足迹减排潜力较高;湘阴县灰水足迹具有较高的潜在缩减规模和水环境压力降低潜势,应成为农业面源污染的重点防控区域。结论]通过农业结构优化、测土配方施肥等多途径与措施,减少灰水足迹排放,以缓解当地水环境压力。研究成果可为粮食主产区水环境调控与农业可持续发展提供理论与方法依据。

MEASUREMENT AND EVALUATION OF AGRICULTURAL ENVIRONMENTAL EFFICIENCY AND ENVIRONMENTAL SUSTAINABILITY FOR WATER IN THE MAJOR GRAIN-PRODUCING AREA BASED ON GREY WATER FOOTPRINT

The non-point source pollution caused by agricultural production has been a key factor affecting the quality of the regional water environment. It is an important research topic to improve the efficiency of agricultural environment under the constraints of water environment in the field of sustainable agricultural development. Under the concept of green development, it is necessary for making quantitative measurement and evaluation for water environment status and resource utilization in major grain-producing area. Based on grey water footprint, this research took 34 major grain-producing counties in Dongting lake area as the research objects, analyzed spatial and temporal evolution characteristics of agricultural environmental efficiency, and evaluated the environmental sustainability based on the panel data of major grain-producing area from 1994-2014, then measured the environmental efficiency of agricultural production by using the Slacks-Based Measure (SBM)-Undesirable window analysis. In addition, the potential models of agricultural resource saving and grey water footprint reduction, scale reduction and water environment pressure reduction were established for analyzing water environment status and resource utilization. The research were showed as follows. (1) Taking Grey water footprint (GWF) as the undesirable output in this SBM model, the environmental efficiency of Dongting lake areas was relatively lower, and the GWF had a higher reduction potential form 1994 to 2014. (2) From the perspective of spatial distribution, the distribution of agricultural environmental efficiency was characterized by large spatial differences. The high environmental efficiency of DMU was mainly located around Dongting lake and far from the lake area. The DMU with environmental efficiency value of 1 was increasing year by year, and the distribution tended to be balance. (3) The grey water footprint reduction potential of agricultural production were higher than other counties in Xiangyin and Huarong. It had a higher potential to reduce scale and water environmental pressure in Xiangyin, it should be the key area for prevention and control of agricultural non-point source pollution. In summary, It should adjust the industrial structure of agriculture, soil testing and formula fertilization way and measures such as reducing emissions and grey water footprint to alleviate the local water environment pressure. The research results can provide theoretical and method basis for water environment regulation and sustainable development of grain producing areas.