Washington D.C.: Increasing irrigation efficiency through irrigation technologies alone is failing to reduce water consumption and, paradoxically, may even be making water scarcity worse, a major new study has found.
The research – published in Science was led by Professor Quentin Grafton of the ANU Crawford School of Public Policy, working with an international and multi-disciplinary team of 11 scientists and economists from eight countries, seven universities and three world-leading research organisations, including the International Food Policy Research Institute (IFPRI) in Washington DC. It aims to respond to one of the greatest policy dilemmas of today: how to reconcile increasing freshwater demands with finite freshwater resources.
Irrigation accounts for 70 percent of global water extractions, more than 80 percent of consumption and provides about 40 percent of the world’s food calories. Thus, understanding how increases in irrigation efficiency change water availability is critical to solving the world’s water problems.
A key research finding, noted by lead author Grafton is that “Increases in irrigation efficiency may result in greater on-farm water consumption, groundwater extractions and even water consumption per hectare. Hence, the paradox – increases in irrigation efficiency may make water scarcity worse, not better.” This paradox is due to increased water use by existing crops, a switch to more water-intensive crops, or an expansion of irrigated areas, all due to improved field application under advanced irrigation technologies.
Co-author Dr. Claudia Ringler from IFPRI adds that “while the hydrology of advanced irrigation and the rational behavior of irrigators to more efficient and reliable water access have been documented for decades, policymakers and investors continue to focus on single-minded technology solutions—supporting food security over water security and ecosystem health, which will eventually harm all three goals.”
The study shows that for advanced irrigation technology to reduce water scarcity, investments need to be accompanied by hydrologic assessment and monitoring of water flows, a limit on water off-take for irrigation; an assessment of risks and uncertainties; the valuation of trade-offs; and a better understanding of the incentives and behavior of irrigators.
“Unless current irrigation policies are reformed, the world will not achieve the Sustainable Development Goals,” said Grafton. “We know what to do. We must act now to avoid a global water tragedy.”
The paper, The Paradox of Irrigation Efficiency, published in Scinece is available online at http://science.sciencemag.org/content/361/6404/748
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The International Food Policy Research Institute (IFPRI) seeks sustainable solutions for ending hunger and poverty. IFPRI was established in 1975 to identify and analyze alternative national and international strategies and policies for meeting the food needs of the developing world, with particular emphasis on low-income countries and on the poorer groups in those countries Visit: www.ifpri.org