Building a climate resilient farm: A risk based approach for understanding water, energy and emissions in irrigated agriculture

Sensitivity analysis revealed the contributionof climatic (evapotranspiration and rainfall) and technical factors (irrigation system efficiency, pumpefficiency, suction and discharge head) impacting the uncertainty and the model output and waterenergysystemperformance in general. Flood irrigation systems were generally associated with greateruncertainty than pressurised systems. To enhance resilience at the farm level, the optimum situationenvisaged an irrigation system that minimises water and energy consumption and greenhouse gas emissions.Where surface water is used, well designed and managed flood irrigation systems will minimisethe operating energy and carbon equivalent emissions. Where groundwater is the dominant use, the optimumsystem is a well designed and managed pressurised system operating at the lowest discharge pressurepossible that will still allow for efficient irrigation. The findings might be useful for farm level riskmitigation strategies in surface and groundwater systems, and for aiding adaptation to climate change.The links between water application, energy consumption and emissions are complex in irrigated agriculture.There is a need to ensure that water and energy use is closely considered in future industry planningand development to provide practical options for adaptation and to build resilience at the farm level.There is currently limited data available regarding the uncertainty and sensitivity associated with waterapplication and energy consumption in irrigated crop production in Australia. This paper examines waterapplication and energy consumption relationships for different irrigation systems, and the ways in whichthe uncertainty of different parameters impacts on these relationships and associated emissions foractual farms. This analysis was undertaken by examining the current water and energy patterns of cropproduction at actual farms in two irrigated areas of Australia (one using surface water and the othergroundwater), and then modelling the risk/uncertainty and sensitivity associated with the link betweenwater and energy consumption at the farm scale. Results showed that conversions from gravity to pressurisedirrigation methods reduced water application, but there was a simultaneous increase in energyconsumption in surface irrigation areas. In groundwater irrigated areas, the opposite is true; the use ofpressurised irrigation methods can reduce water application and energy consumption by enhancingwater use efficiency. Risk and uncertainty analysis quantified the range of water and energy use thatmight be expected for a given irrigation method for each farm.