Goswami Prashant, Nishad Shiv Narayan
CSIR Fourth Paradigm Institute (erstwhile CSIR Centre for Mathematical Modelling and Computer Simulation), Wind Tunnel Road, Bangalore, India-560037.
Sci Rep. 2015 Mar 20;5:9306. doi: 10.1038/srep09306.
Assessment and policy design for sustainability in primary resources like arable land and water need to adopt long-term perspective; even small but persistent effects like net export of water may influence sustainability through irreversible losses. With growing consumption, this virtual water trade has become an important element in the water sustainability of a nation. We estimate and contrast the virtual (embedded) water trades of two populous nations, India and China, to present certain quantitative measures and time scales. Estimates show that export of embedded water alone can lead to loss of water sustainability. With the current rate of net export of water (embedded) in the end products, India is poised to lose its entire available water in less than 1000 years; much shorter time scales are implied in terms of water for production. The two cases contrast and exemplify sustainable and non-sustainable virtual water trade in long term perspective.
对耕地和水等主要资源可持续性的评估及政策设计需要采用长远视角；即使是像水的净出口这样微小但持续的影响，也可能通过不可逆转的损失影响可持续性。随着消费的增长，这种虚拟水贸易已成为一个国家水资源可持续性的重要因素。我们估算并对比了两个人口大国印度和中国的虚拟（内含）水贸易情况，以呈现某些定量指标和时间尺度。估算结果表明，仅内含水的出口就可能导致水资源可持续性的丧失。按照目前最终产品中水（内含）的净出口率，印度在不到1000年的时间里就可能耗尽其全部可用水资源；就生产用水而言，所需时间尺度更短。这两个案例从长远角度对比并例证了可持续和不可持续的虚拟水贸易。
