College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China.
College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China.
Sci Total Environ. 2022 Apr 20;818:151810. doi: 10.1016/j.scitotenv.2021.151810. Epub 2021 Nov 20.
Improving the resource utilization efficiency in irrigation systems contributes to the sustainability of the regional water-energy-grain nexus. Based on the water, energy and grain relationships quantification, the comprehensive efficiency (CE) of water transfer and grain production processes and its driving mechanism were analyzed, considering a pumping irrigation system in the Lianshui irrigation district (LID) in eastern China, as a case study. The annual crop output, crop water footprint, and electric energy consumption were estimated as 905.3 M kg (1 M = 10), 914.7 M m (50.7% blue water), and 3004.0 kWh, respectively, from 2005 to 2018; the corresponding crop water productivity (CWP), electricity energy productivity (EEP), water intake efficiency of electric energy (WIE) were 0.91 kg/m, 80.39 kg/kJ, and 75.22 m/kJ, respectively. CWP, EEP, and WIE varied among crops; however, none of the three indicators showed an obvious trend of change with time. The CE of integrated grain was 0.48 and showed an increase over time, indicating that the sustainability of the studied pumping irrigation system was improving. The driving effect of artificial factors (e. g. social development, agricultural input, and water management) on the CE was more obvious than that of natural conditions (e. g. climate). Increasing agricultural machinery and urbanization rates and reducing the agricultural water rate are conducive to improving the resource utilization efficiency in pumping irrigation systems. The analysis framework coupling water footprint and traditional paradigms proposed in this paper provides a feasible approach for the stability and sustainability of irrigated agricultural systems observation.
提高灌溉系统的资源利用效率有助于区域水-能源-粮食关系的可持续性。本研究基于水-能源-粮食关系量化方法，以中国东部涟水灌区的提水灌溉系统为例，分析了输水过程和粮食生产过程的综合效率（CE）及其驱动机制。结果表明，2005—2018 年，该灌区的年作物产量、作物耗水足迹和耗电量分别为 905.3×10^4kg、914.7×10^6m^3（50.7%为蓝水）和 3004.0×10^3kWh；相应的作物水分生产率（CWP）、电能生产率（EEP）和电能取水量效率（WIE）分别为 0.91kg/m^3、80.39kg/kJ 和 75.22m/kJ。CWP、EEP 和 WIE 在作物间存在差异，但没有一个指标随时间呈现明显的变化趋势。综合粮食的 CE 为 0.48，且呈上升趋势，表明研究区提水灌溉系统的可持续性在不断提高。人工因素（如社会发展、农业投入和水资源管理）对 CE 的驱动效应比自然条件（如气候）更为明显。提高农业机械化率和城市化率，降低农业用水定额，有利于提高提水灌溉系统的资源利用效率。本研究提出的水足迹与传统方法相结合的分析框架为灌溉农业系统稳定性和可持续性观测提供了一种可行的方法。
