Non-renewable groundwater use, deﬁned as groundwater removal that is greater than recharge, has drastically increased over the last decades due to rapidly growing food demand. Crops produced in irrigated areas now account for 40% of global food production . However, the strain on the environment is becoming increasingly clear, and recent studies show that current practice is not sustainable .
This study associates speciﬁc crops with non-renewable water use by estimating a spatially detailed water balance for 26 major crops considering crop-speciﬁc cultivation dates, water requirements, natural recharge, recharge from irrigation, and groundwater abstraction in production areas. Embodied non-renewable groundwater in products is then tracked in the global trade network to the end user. The global model runs on a 0.5° grid from 2010 to 2054 on a monthly time step under SSP2 for 5 GCMs.
Preliminary results show an increase in global non-renewable groundwater use in the future (Figure 1). Intensive production areas in the Indus Basin, Northeast China, and the USA show substantial non-renewable groundwater use. Rice, wheat, and maize are most important crops grown.
This study adds further proof to the expectation that non-renewable groundwater use will increase in the future and that important agricultural areas are at risk if no mitigation measures are taken. It is shown that certain water-intensive crops are grown in heavily irrigated areas where water availability is limited. Decision makers could benefit from this research by careful consideration of future crop allocation, using caution in extension of irrigated areas, and improving irrigation systems.
 Molden D, Oweis TY, Pasquale S, Kijne JW, et al. (2007). Pathways for increasing agricultural water productivity. In Molden D. (Ed.). Water for food, water for life: a Comprehensive Assessment of Water Management in Agriculture. London, UK: Earthscan; Colombo, Sri Lanka: International Water Management Institute.
 Wada Y, Beek LPH, and Bierkens MFP (2012). Nonsustainable groundwater sustaining irrigation: A global assessment. Water Resources Research 48, 6.
Günther Fischer and Sylvia Prieler, Water Program, IIASA
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Last edited: 03 February 2016
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