基于实体-虚拟二元框架的灌区水循环演变过程及可持续性分析

Large volume of real water resources are transferred to the irrigation districts, while large volume of virtual water resources flowed between the irrigation districts and other areas every year. The water shortage has been more serious in recent years, which has become one of the main bottlenecks for the development of irrigation districts. As important crop producing areas, large volume of water resources are consumed in the irrigation districts. The complement of water management system in the irrigation districts is helpful for the implementation of the most stringent water resources management system, which is of great significance for the security of water and food in China. The scientific evaluation system for water resources in the irrigation districts is the prerequisite for this. In this project, the real and virtual water cycles are combined, considering the water balance and relationships between different elements. And then the elements of the real-virtual water cycle are analyzed using regression analysis method considering the volume, direction and components. Lastly, the evaluation system including natural, social and economic factors is build for the sustainable development of the real-virtual water cycle in the irrigation districts, considering the driver, press, state, impact and response of different elements. And the situation in Hetao irrigation district is analyzed using this evaluation system. The implementation of this project could help to provide the scientific basis for the implication of water management system in the irrigation distracts and references for the improvements of regional production, consumption and trade.

灌区同时存在大规模实体引水与虚拟调水现象。近年，灌区水资源短缺现象日益严峻，成为制约其可持续发展的主要瓶颈之一。作为重要的耗水单元与粮食生产区域，完善灌区水资源管理框架，有助于实现最严格的水资源管理制度，对国家水资源和粮食安全意义重大。而实现该目标必须首先建立合理的灌区水资源分析评价体系。本项目拟借助水量平衡和循环要素间水力联系，将实体水循环与虚拟水循环结合，建立灌区实体-虚拟二元水循环框架；之后，采用回归分析等方法，从流量、流向及构成角度分析河套灌区实体-虚拟二元框架主要构成要素的演变过程及特征；最后，考虑自然、经济、社会角度，从驱动力、压力、状态、影响、响应等方面出发，建立基于二元框架的灌区水循环可持续性评价体系，并对河套灌区进行实证分析。项目研究成果可为灌区水资源管理体系完善提供理论基础，并为灌区生产、消费、贸易模式调整提供参考。

随着社会经济不断发展，灌区的水资源短缺现象日益严峻，成为制约其可持续发展的主要瓶颈之一。作为重要的耗水单元与粮食生产区域，如何建立合理的灌区水资源分析评价体系、完善灌区水资源管理框架，对实现最严格的水资源管理制度，保障国家水资源和粮食安全意义重大。本项目（1）构建了灌区尺度不同类型产品水足迹及虚拟水流动计算体系，明晰了区域实体与虚拟水循环过程，结果表明2001-2010年河套灌区生产水足迹、消费水足迹与虚拟水流动量分别为43.00，9.84和33.16亿m3，各指标最大值分别出现在五原县（12.27亿m3）、临河市（2.73亿m3）和五原县（10.42亿m3），作物水足迹与虚拟水流动量均明显大于其他农产品与工业产品，占灌区总量的80%以上，蓝水为灌区水足迹及虚拟水流动的主要构成部分；（2）综合考虑生产、消费和贸易角度，构建了灌区尺度蓝水资源压力指数，结果表明河套灌区为高水资源压力地区，从生产角度出发，农业部门为最大的水资源压力部门，从消费角度出发，产品出口为主要的水资源压力驱动要素，结合贸易要素，将实体和虚拟水调运共同考虑，灌区水资源压力从0.242增加至0.491；（3）建立了区域水资源消耗评价指标体系，结果表明蓝水足迹占灌区蓝水可用量的比例为0.642，区域生产行为对其他地区的消费贡献率约为0.9，其他地区的产品进口对河套灌区当地的水资源消耗贡献率分别为0.528（蓝水）和0.433（绿水）；（4）将水足迹、虚拟水理论与生命周期评价方法结合，建立了区域水资源消耗环境影响分析方法，并进行案例分析，结果表明实体水调运和虚拟水流动对生态质量的影响分别为1.33×109 m2·yr (正值)和867.60×106 m2·yr (负值) ，实体水调运和虚拟水流动对当地水资源的影响分别为28.16×109 MJ (正值)和 18.26×109 MJ (负值) ，灌区中部地区的环境影响更为显著。该研究为完善灌区水资源分析体系、指导灌区生产实践提供理论依据，同时为在灌区尺度实施最严格的水资源管理制度提供参考。