FutureWater was hired to use satellite-derived data to provide a preliminary spatiotemporal assessment of water consumption across the Border Rivers catchment, one of the MDB catchments where excessive agricultural water use is an urgent issue. For relevant specific lots / properties, monthly water consumption dynamics were evaluated. This study is a demonstration of the type of information that could be obtained from a more sophisticated, validated and potentially near-real-time system for monitoring and evaluation of agricultural water consumption.
Efforts are being made in the Australian Murray-Darling Basin (MDB) to transfer water from the irrigation sector to environmental flows. However, discussions have been on-going for several years regarding the appropriate way to achieve this goal. Dimensions under discussion include the promotion of improving on-farm irrigation efficiencies, water rights and their buybacks, undocumented use of water for irrigation, and “theft” of water.
A knowledge gap exists regarding the actual amount of water that is being consumed across the MDB, which is the main outgoing component of the basin water balance. Spatial quantification of actual evapotranspiration (ETact) would, for example, allow for estimation of irrigation water consumption in relation to water allocation, and thus support identification of locations where theft of water occurs.
Mapping of ETact has been developed by the scientific community for the past 20 years and has now achieved a degree of technological maturity. This has prompted the distribution of several global ETact products in the public and semi-public domains, which offer a revolutionary and cost-effective way for evaluating and monitoring water consumption. Remote sensing data have been used to analyze water extractions and storage, but not yet for quantification of consumptive use.
A global-scale ETact product was applied in this demonstration project to provide preliminary figures and maps on monthly and yearly water consumption in the Border Rivers subcatchment on different spatial scales.
2018 - FutureWater Report 177
Agricultural Water Consumption in the Australian Border Rivers Catchment: a Preliminary Assessment
Simons, G.W.H., M. Kruisheer