The main objective of this study was to assess the potential impacts of climate change on water productivity (WP) in the Mediterranean region considering different water inputs. Climate data were derived from the ENSEMBLES RCM simulations for the present (1991-2010) and the future situation (2036-2065) under the SRES scenario A1B. Expected changes of crop water requirements (CWR), net irrigation requirements (NIR), relative yield loss (RYL) and water productivity between baseline and future scenarios, under optimal and limited water supply, were estimated for two important Mediterranean crops: winter wheat and tomato. In general, a decrease of CWR and NIR for both crops and for all simulated irrigation scenarios is expected due to shorter growing season. Therefore, the air temperature increase could have a dominant role in shortening the growing season rather than increasing CWR.
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The impact of climate change on CWR and NIR would be greater under optimal rather than limited water supply. Under limited water supply, RYL would slightly decrease due to expected change in rainfall pattern. In general, a slight increase of WP is expected for both crops due to the combined effect of temperature, precipitation and CO2.
