Record Details

Future irrigation expansion outweigh groundwater recharge gains from climate change in semi-arid India

OAR@ICRISAT

View Archive Info
 
 
Field Value
 
Relation http://oar.icrisat.org/10802/
http://dx.doi.org/10.1016/j.scitotenv.2018.04.130
10.1016/j.scitotenv.2018.04.130
 
Title Future irrigation expansion outweigh groundwater recharge gains from climate change in semi-arid India
 
Creator Sishodia, R P
Shukla, S
Wani, S P
Graham, W D
Jones, J W
 
Subject Semi-arid tropics
Irrigation
Climate Change
Water Resources
Indian Agriculture
Water Conservation
 
Description Simultaneous effects of future climate and irrigation intensification on surface and groundwater systems are not well understood. Efforts are needed to understand the future groundwater availability and associated surface flows under business-as-usual management to formulate policy changes to improve water sustainability. We combine measurements with integrated modeling (MIKE SHE/MIKE11) to evaluate the effects of future climate (2040–2069), with and without irrigation expansion, on water levels and flows in an agricultural watershed in low-storage crystalline aquifer region of south India. Demand and supply management changes, including improved efficiency of irrigation water as well as energy uses, were evaluated. Increased future rainfall (7–43%, from 5 Global Climate Models) with no further expansion of irrigation wells increased the groundwater recharge (10–55%); however, most of the recharge moved out of watershed as increased baseflow (17–154%) with a small increase in net recharge (+0.2 mm/year). When increased rainfall was considered with projected increase in irrigation withdrawals, both hydrologic extremes of well drying and flooding were predicted. A 100-year flow event was predicted to be a 5-year event in the future. If irrigation expansion follows the historical trends, earlier and more frequent well drying, a source of farmers' distress in India, was predicted to worsen in the future despite the recharge gains from increased rainfall. Storage and use of excess flows, improved irrigation efficiency with flood to drip conversion in 25% of irrigated area, and reduced energy subsidy (free electricity for 3.5 h compared to 7 h/day; $1 billion savings) provided sufficient water savings to support future expansion in irrigated areas while mitigating well drying as well as flooding. Reductions in energy subsidy to fund the implementation of economically desirable (high benefit-cost ratio) demand (drip irrigation) and supply (water capture and storage) management was recommended to achieve a sustainable food-water-energy nexus in semi-arid regions.
 
Publisher Elsevier
 
Date 2018-09
 
Type Article
PeerReviewed
 
Format application/pdf
 
Language en
 
Rights —
 
Identifier http://oar.icrisat.org/10802/1/Future%20irrigation%20expansion%20outweigh%20groundwater%20recharge%20gains%20from%20climate%20change%20in%20semi-arid%20India.pdf
Sishodia, R P and Shukla, S and Wani, S P and Graham, W D and Jones, J W (2018) Future irrigation expansion outweigh groundwater recharge gains from climate change in semi-arid India. Science of The Total Environment (TSI), 635. pp. 725-740. ISSN 00489697