College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China; Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment, Ministry of Education, Hohai University, Nanjing 210098, China.
College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China.
Sci Total Environ. 2020 Jul 10;725:138537. doi: 10.1016/j.scitotenv.2020.138537. Epub 2020 Apr 7.
Water footprint regulation in agricultural production is of great significance to regional food, water and ecological sustainability. The spatial-temporal characteristics and driving mechanism of water footprint efficiency (WFE) in crop cultivation in China during 1996-2015 were analysed based on the quantification of the crop-water relationship. The results showed that China's total crop water footprint (TWF) was 1125.6 G m, and the blue, green and grey components accounted for 24.4%, 57.4% and 18.2%, respectively. The national WFE was 0.681 and increased over time due to the improvement of agricultural technology. Spatial autocorrelation analysis showed that provinces with similar WFE values were clustered geographically and have gradually weakened since 2012. Provinces with a high WFE were concentrated in the southeast and northeast, and low-value provinces were distributed in the west of China. The main anthropogenic driving factors were the preliminary fertilizer application intensity (FAI) and population density (PD); however, these factors have been replaced by the irrigation efficiency (IE), agricultural water use ratio (AWR) and irrigation area proportion (IAP) in recent years. Specific regions should formulate water resource management policies according to their WFE performance, agricultural production scale and water resource endowment. The northeast should control crop cultivation and enhance the yield to solve water shortage problems, the central provinces should improve WFE, and the southern provinces should contribute to the promotion of national water use efficiency by expanding crop sowing and irrigation areas. This study provides a reference for water resource management in the context of social and environmental change.
农业生产的水足迹调控对区域粮食、水和生态可持续性具有重要意义。本研究基于作物需水量的量化，分析了 1996-2015 年中国作物种植水足迹效率（WFE）的时空特征及其驱动机制。结果表明，中国作物总需水量（TWF）为 1125.6 Gm3，其中蓝水、绿水和灰水分别占 24.4%、57.4%和 18.2%。全国 WFE 为 0.681，且随时间呈上升趋势，这主要归因于农业技术的进步。空间自相关分析表明，具有相似 WFE 值的省份在地理上呈聚集分布，且自 2012 年以来这种分布逐渐减弱。WFE 较高的省份集中在东南和东北地区，低值省份则分布在中国西部。主要的人为驱动因素是初始施肥强度（FAI）和人口密度（PD）；但近年来，这些因素已被灌溉效率（IE）、农业用水比例（AWR）和灌溉面积比例（IAP）所取代。特定地区应根据其 WFE 表现、农业生产规模和水资源禀赋制定水资源管理政策。东北应控制作物种植面积，提高单产以解决水资源短缺问题，中部省份应提高 WFE，南方省份应通过扩大播种面积和灌溉面积来促进全国用水效率的提高。本研究为社会和环境变化背景下的水资源管理提供了参考。
