Effects of modernization and medium term perspectives on water and energy use in irrigation districts

摘要

Increasing of water use efficiency has been a key strategy for dealing with water scarcity in semiarid countries. In Spain modernization of irrigation schemes has consisted in the substitution of old open channels systems by pressurized networks. However, this improvement has represented a significant increase in water costs, mainly due to the higher energy requirements.Five irrigation districts of Andalusia, Southern Spain, have been analyzed using performance indicators, before and after the improvement actions. Results indicate an average reduction in water diverted for irrigation of 23%, but water costs increased in 52%. Consequently, farmers are migrating to more profitable crops, such as citrus, with higher water requirements. Furthermore, managers' predictions about the cropping patterns for the 20205 suggest that the area devoted to citrus production will increase by 12%, implying even higher potential maximum irrigation water demand. Hence, farmers will have to adapt to a future scenario by using deficit irrigation and other water saving technologies. Consequently, the vulnerability of the irrigated agriculture to the typical droughts of the Mediterranean climate may increase