Satellite remote sensing of crop water use in an irrigation area of south-east Australia

Irrigation has a significant impact on water resources. It is therefore important that objective assessments of the use of irrigation water are undertaken on a regular basis. Current affordable remote sensing technologies provide an opportunity to assess and monitor water use at farm and regional scales. This study demonstrates the use of satellite-based estimates of evapotranspiration (ET) and NDVI in irrigation performance indicators that relate crop water use to crop water requirement in an irrigation region of Australia. A modified energy balance algorithm was used to derive ET estimates using Landsat-7 ETM+ data. Results show a consistent trend of slightly over-supply of crop water as compared to actual requirement at both field and farm scales during the peak irrigation season in 2011–12.