A Spatial Dynamic Framework to Intergrate Regional Water Use Efficiency and Energy Consumption

Water and energy are the principal inputs in agricultural production systems. Efficient use of surface and ground water and energy resources is vital in terms of productivity and economic competitiveness of agriculture as well as for environmental sustainability. The need to reduce dependency on increasingly scarce energy resources, prevent water quality and environmental deterioration and the opportunity to develop the agricultural potential for producing high yielding crops, demand an integrated understanding of hydrologic, economic and environmental dynamics of high-input farming systems, especially high energy consuming pressurized irrigation technologies. Analysing the nexus of water and energy dynamics is a complex scientific and policy issue. The thesis recognizes the fact that the water saved from on-farm irrigation efficiency gains and that saved from conveyance losses not only reduces cost per megalitre to the irrigators; it can also be made available to the environment and therefore helps achieve both environmental and economic benefits. Improving water use efficiency by adopting measures and methods that reduce seepage, evaporation and deep percolation etcetera results in increased energy consumption. Investments to boost water efficiency and to improve energy productivity are two possible pathways to reduce the environmental footprints of crop production. However, these two pathways may pose conflicting outcomes. This PhD research is primarily aimed at investigating the both pathways and to recommend a mix of policy options that are likely to result in optimal outcome. This is also important in the context of new Murray-Darling Basin Plan which may result in significant reductions in irrigation diversions for the Murrumbidgee Irrigation Area (MIA).