Agricultural adaptation to reconcile food security and water
sustainability under climate change: the case of cereals in Iran
Abstract
In this study, we simulate the crop yield and water footprint (WF) of
major food crops of Iran, for the historical (1980-2010) and the future
(2041-2070) climate. Then, we assess the effects of three agricultural
adaptation strategies to climate change in terms of potential blue water
savings and the degree to which these savings reduce unsustainable blue
water consumption. These adaptation strategies are (i) off-season
cultivation, (ii) early planting, and (iii) benchmarking the WF of
cereals. We find that the annual consumptive water use increases in both
irrigated and rainfed croplands. This is most noticeable in the arid
regions, where consumptive water use increases by roughly 70% under
climate change. To alleviate additional pressure on blue water
resources, off-season cultivation is the most effective adaptation
strategy with blue water savings of 14-15 billion m3
y-1. However, this strategy is accompanied by
significant production losses. Second most effective is WF benchmarking
which results in blue water savings of 1.1-3.5 billion
m3 y-1. The early planting strategy
is less effective, but still leads to blue water savings of 1.7-1.9
billion m3 y-1. In the same order of
effectiveness, these three strategies can reduce blue water scarcity and
unsustainable blue water use in Iran under current conditions. However,
we find that these strategies don’t mitigate water scarcity in all
provinces, nor in all months of the year. Further research is required
to find adaptation strategies to reconcile food security and sustainable
water use throughout the country, with consideration of socio-economic
impacts as well.