Abstract Water shortages pose significant threats to local water security and food production around the world. Water managers have resorted to various water resources planning measures to overcome these challenges. For the first time and for a case study in Iran, we provide a comparative analysis of two such measures: physical and virtual inter-basin water transfers (IBWT). We evaluate green and blue water footprints (WF) associated with the production of 39 crops grown in humid Mazandaran and arid Semnan provinces, under (i) current production patterns and current local water availability; (ii) current production patterns and a planned physical IBWT scheme between Mazandaran (donor) and (receiving) Semnan province to provide water to water-intensive crops in the latter; (iii) modified cropping patterns, such that surplus production of water-intensive crops in Mazandaran abates production in Semnan province, coupled with interprovincial trade (i.e., a virtual IBWT scheme). We find that crops currently produced in Mazandaran have considerably lower blue WFs per unit of production (m3 t−1) and a higher economic blue water productivity (EBWP, $ m−1) than in Semnan province. A physical IBWT would reduce blue water scarcity (BWS) in Semnan province by 34%, but at the cost of reduced EBWP by up to 46% of crops irrigated with the more costly transferred water. A virtual IBWT would reduce BWS in Semnan province to the same degree, while only modestly increasing BWS in Mazandaran province (from 0.15 to 0.21, indicating that Mazandaran water resources can sustainably support the proposed increase in production). Moreover, Mazandaran's provincial average EBWP is even raised (by 7%) in the virtual IBWT scenario.

中文翻译：

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克服当地水资源短缺的物理与虚拟水转移：影响比较分析

摘要 水资源短缺对世界各地的当地水安全和粮食生产构成重大威胁。水资源管理者采取了各种水资源规划措施来克服这些挑战。对于伊朗的案例研究，我们首次对两种此类措施进行了比较分析：物理和虚拟跨流域调水 (IBWT)。我们根据 (i) 当前的生产模式和当前的当地可用水量评估了与在潮湿的马赞达兰省和干旱的塞姆南省种植的 39 种作物的生产相关的绿色和蓝色水足迹 (WF)；(ii) Mazandaran（捐助者）和（接收）Semnan 省之间目前的生产模式和计划的物理 IBWT 计划，为后者的耗水作物提供水；(iii) 改良的种植模式，因此，马赞德兰省水资源密集型作物的过剩生产减少了塞姆南省的生产，再加上省际贸易（即虚拟 IBWT 计划）。我们发现，与塞姆南省相比，马赞达兰目前生产的作物每单位生产的蓝色 WF（m3 t-1）和更高的经济蓝水生产力（EBWP，$ m-1）要低得多。物理 IBWT 可以将 Semnan 省的蓝水短缺 (BWS) 减少 34%，但代价是使用成本更高的转移水灌溉的作物的 EBWP 减少​​了 46%。虚拟 IBWT 会将塞姆南省的 BWS 降低到相同程度，而马赞达兰省的 BWS 只会适度增加（从 0.15 到 0.21，表明马赞达兰水资源可以持续支持拟议的增产）。此外，马赞德兰