1989—2019年陕西省作物生产水足迹时空演变与节水潜力评价

【目的】陕西省是中国重要的粮油果基地，却大部分地处半干旱区，有限的水资源是制约当地经济社会可持续发展的最大刚性约束。作物生产耗水及节水潜力定量评价是农业适水发展与绿色高效节水的基础性工作。【方法】本文基于1989—2019年陕西省地级市尺度10种主要作物在灌溉、雨养条件下作物生产蓝水足迹(灌溉水消耗)、绿水足迹(有效降水消耗)和灰水足迹(稀释污染负荷所需水量)时空演变特征，推演典型年作物生产工程节水潜力和真实节水潜力。【结果】结果显示：(1)近30年陕西省各作物生产消耗型水足迹均呈整体下降趋势，同一作物生产水足迹在市际间存在较大差异。省平均苹果生产消耗型水足迹下降幅度达91.3%；各市间小麦生产消耗型水足迹差异值可达3.41 m³/kg，同时，苹果和油菜籽生产灰水足迹呈上升趋势。(2)省作物生产消耗型总水足迹在2019年达160.55亿m³/a，较1989年微降1.8%；玉米、小麦和苹果贡献了省作物生产消耗型总水足迹的80%以上。(3)陕西省作物生产工程节水潜力、蓝水真实节水潜力和绿水真实节水潜力分别可达62%、68%和49%。【结论】陕西省...

Spatiotemporal evolution of water footprint and water-saving potentials of crop production in Shaanxi Province during 1989-2019

Objective] Shaanxi Province is an important grain, oil, and fruit production base in China, but most part of the province is located in the semi-arid zone. Limited water resources are the biggest constraint to the sustainable development of local economy and society. Quantitative evaluation of water consumption and water-saving potentials in crop production is crucial for water resource-adapted agricultural development and green and high-efficiency water-saving. Methods] Based on the spatiotemporal evolution characteristics of the annual blue water footprint (irrigation water consumption) and green water footprint (effective precipitation consumption) of growing 10 major crops under irrigated and rainfed conditions in Shaanxi Province from 1989 to 2019, the engineering water-saving potential and real water-saving potential of crop production in typical years were deduced. Results] The results show that: (1) The consumptive water footprint per yield of all crops in Shaanxi Province showed an overall downward trend in the 30-year study period, and the water footprint of individual crops had visible differences between cities. The provincial average unit consumptive water footprint of apple production decreased by 91.3%; the difference of consumptive water footprint of wheat production between cities reached 3.41 m³/kg. At the same time, the grey water footprint of apple and rapeseed production showed an increasing trend. (2) The total consumptive water footprint of crop production was 16.055 billion m³/a in 2019, slightly decreased by 1.8% from 1989. Corn, wheat, and apple production contributed more than 80% of the total consumptive water footprint of provincial crop production. (3) The water-saving potential, blue water saving potential, and green water saving potential of crop production in Shaanxi Province were 62%, 68%, and 49%, respectively. Conclusion] There is a great potential of agricultural water-saving in Shaanxi Province. There are two preliminary suggestions: (1) Combining technology and management measures to accelerate agricultural water-saving and efficiency; (2) Accelerate scientific and accurate fertilization to reduce environmental pressure.