Climate change impacts on pressurised irrigation systems

Investment in collective pressurised irrigation infrastructure has played a major role in intensifying agricultural production in southern Italy, with positive impacts on the rural economy and sustainability of livelihoods. However, due to observed climate trends and intensified agricultural practices, this region has been identified as being most susceptible to desertification in Europe. This work uses a case study to assess agronomic impacts of climate change on crop water demand and engineering impacts on the performance and sustainability of existing irrigation infrastructure to meet peak demands. Outputs from a general circulation model for selected Intergovernmental Panel on Climate Change emission scenarios were downscaled and applied to baseline climatology. A water balance model was used to assess changes in irrigation water requirements and hydraulic modelling was then used to assess the impacts of engineering design on the future sustainability of the system's performance. The results indicate that climate changes will increase the number of failing hydrants up to 54-60%. Furthermore, system costs will increase by 20-27% when designed according to the future irrigation demand. Water managers, farmers and agribusinesses need to develop adaptation strategies to cope with changes in future water reliability. The paper also discusses the implications of alternative options such as the use of low-energy systems, improving irrigation efficiency, switching to deficit irrigation and changing cropping patterns.