干旱区生态环境知识资源中心

This work is focused on the analysis of the interdependence between water and energy consumption in the irrigation agriculture sector. The quantification of water and energy use in the Mediterranean region is interesting for planners and managers in water agencies and collective irrigation associations, especially if irrigation district modernisation processes and different water scarcity intensities have occurred throughout the study period. The results can also be useful for formulating recommendations for rationalising water and energy use in irrigated crop production. The study assesses energy consumption for irrigation throughout a 10-year period, particularising for different management levels and locations under the semi-arid conditions of south-eastern Spain. A set of performance indicators was selected to characterise water and energy relationships at three management levels: basin, irrigation district, and farm. Five kinds of water source were found for the selected irrigation districts: surface water, groundwater, external water transfer, recycled water, and desalinated brackish water. From the present work it can be seen that the increased energy consumption per m(3) of water supplied or specific energy occurred at basin level, representing between 71 and 82 % of the total. At this level the most influential factor for energy consumption was the waters source, with surface water having the lowest specific energy, and desalinated brackish water the highest. The specific energy consumed at irrigation district level represented between 12 and 15% of the total, with very similar consumptions in the three irrigation districts considered in this work. At farm level, the availability of pressurised collective networks lowered energy consumption for irrigation when the allocation method was on-demand, whereas it implied the re-pressurisation of the irrigation system when the allocation method is rotational scheduling. In the latter case, specific energy at farm level was 17% of the total.