基于水污染视角的中国农业生态用水效率及其影响因素

Ecological Use Efficiency of Agricultural Water and Its Influencing Factors in China Based on the Perspective of Water Pollution

农业水污染给中国农业的可持续用水造成了巨大威胁,研究农业生态用水效率及其影响因素,有助于优化中国农业水资源配置,推动农业可持续发展。基于SBM方向性距离函数,测度2008—2018年中国农业生态用水效率和农业经济用水效率,并对这两种效率的无效率值进行分解和对比;结合Tobit回归模型,探究了农业生态用水效率的影响因素。结果表明:(1)中国农业生态用水无效率始终高于经济用水无效率,农业水污染是农业生态用水无效率的主要来源。(2)农业用水低浪费—低污染的省份数量大幅减少,而高浪费或高污染的省份数量大幅增加。(3)水资源禀赋、水利设施蓄水能力和农村劳动力受教育水平对中国农业生态用水效率产生正向影响,耗水作物种植比例对农业生态用水效率产生负向影响。中国政府应充分认识到农业用水过程中的水污染问题,针对性地在各地实施农业节水战略与水污染防治对策;完善跨区域调水机制、增强水利设施的蓄水能力、提升农村劳动力受教育水平和优化耗水作物的种植比例。

Agricultural water pollution poses a massive threat to the sustainable use of agricultural water in China. Study on the efficiency of agricultural ecological water use and its influencing factors is helpful to optimize the allocation of agricultural water resources and promote the sustainable development of agriculture. Based on the SBM directional distance function, the agricultural ecological water use efficiencies and agricultural economic water use efficiencies of 31 provinces in China from 2008 to 2018 were measured, and the inefficiency values of these two efficiencies were divided and compared. On this basis, the influencing factors of agricultural ecological water use efficiency were analyzed by using the Tobit regression model. The results show that:(1) ecological water use inefficiency in agriculture was higher than the economic water use inefficiency in China, and agricultural water pollution was the main source of ecological water use inefficiency in agriculture;(2) the number of provinces with low waste and low pollution in agriculture water had significantly reduced, while the number of provinces with high waste or high pollution had significantly increased;(3) water resources endowment, water storage capacity of water conservancy facilities and education level of rural labor had positive effects on ecological water use efficiencies of agriculture in China, while the planting ratio of water-consuming crops had negative effects on it. The government in China should be fully aware of the problem of water pollution in the process of agricultural water use, and should implement agricultural water saving strategy and water pollution control measures in various regions, improve cross-regional water transfer mechanism, enhance water storage capacity of water conservancy facilities, improve the education level of rural labor force, and optimize the planting ratio of water-consuming crops.