GRIMOD ALBERTO

The effects of climate change and global warming are expected to create challenging water management problems for many regions around the world. This thesis describes and tests a methodology to investigate how climate change effects can impact the water supply reliability and the environment in an irrigation dominated region. The methodology is based on utilizing a hydrological water allocation model in conjunction with an irrigation model. The predicted climate change series, obtained from Global Climate Model, are used to generate new time series of river flows and irrigation water requirements. These data are then used to run 100+ years of simulations in the allocation model to determine how water supplies and water demands to irrigators change. The method has been successfully tested for the Goulburn Murray Irrigation District, located in the southeast of Australia. Initial results suggest that the impact of climate change on this agricultural region is likely to be severe. In some irrigation districts, the median reliability volume (i.e. the volume of water that is available in 50 year out of 100) may decrease by about 14-35%. In other areas the drop can be from 0-50%. This modeling method can be used to inform policy decisions for climate change adaptation.