Future water resources for food production in five South Asian river basins and potential for adaptation--a modeling study.
The Indian subcontinent faces a population increase from 1.6 billion in 2000 towards 2 billion around 2050. Therefore, expansion of agricultural area combined with increases in productivity will be necessary to produce the food needed in the future. However, with pressure on water resources already being high, and potential effects of climate change still uncertain, the question rises whether there will be enough water resources available to sustain this production. The objective of this study is to make a spatially explicit quantitative analysis of water requirements and availability for current and future food production in five South Asian basins (Indus, Ganges, Brahmaputra, Godavari and Krishna), in the absence or presence of two different adaptation strategies: an overall improvement in irrigation efficiency, and an increase of reservoir storage capacity. The analysis is performed by using the coupled hydrology and crop production model LPJmL. It is found that the Godavari and Krishna basins will benefit most from an increased storage capacity, whereas in the Ganges and the Indus water scarcity mainly takes place in areas where this additional storage would not provide additional utility. Increasing the irrigation efficiency will be beneficial in all basins, but most in the Indus and Ganges, as it decreases the pressure on groundwater resources and decreases the fraction of food production that would become at risk because of water shortage. A combination of both options seems to be the best strategy in all basins. The large-scale model used in this study is suitable to identify hotspot areas and support the first step in the policy process, but the final design and implementation of adaptation options requires supporting studies at finer scales.
Earth System Science and Climate Change, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, Netherlands. Electronic address: hester.biemans@wur.nl.
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H
Biemans
Earth System Science and Climate Change, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, Netherlands.
L H
LH
Speelman
Earth System Science and Climate Change, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, Netherlands.
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F
Ludwig
Earth System Science and Climate Change, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, Netherlands.
E J
EJ
Moors
Met Office Hadley Centre for Climate Prediction and Research, FitzRoy Road, Exeter, Devon EX1 3PB, United Kingdom.
A J
AJ
Wiltshire
Max Planck Institute for Meteorology, Bundesstraße 53, 20146 Hamburg, Germany.
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P
Kumar
Potsdam Institute for Climate Impact Research, Research Domain II: Climate Impacts and Vulnerabilities, Telegraphenberg A62, 14473 Potsdam, Germany.
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D
Gerten
Earth System Science and Climate Change, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, Netherlands; International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg, Austria.
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Kabat
D000383:Agriculture; D002980:Climate; D057231:Climate Change; D003247:Conservation of Natural Resources; D005523:Food Supply / Q000706:statistics & numerical data*; D008962:Models, Theoretical; D045483:Rivers; D062066:Water Resources / Q000706:statistics & numerical data*; D014881:Water Supply / Q000706:statistics & numerical data*
Adaptation; Climate change; Food security; India; Irrigation; Water resources