Summer Irrigated Areas and Irrigation Water Use for the Murray-Darling Basin from 1987 to 2024

This dataset provides a 37‑year record (1987–1988 to 2023–2024) of summer irrigated areas and net irrigation water use (IWUnet) across the Murray–Darling Basin (MDB) at ~30 m spatial resolution. Irrigated areas are classified into six phenology‑based types representing major summer crops, pastures and orchards. The products were derived from gap‑free monthly Landsat‑based Normalised Difference Vegetation Index (NDVI) and actual evapotranspiration (ETa) time series, produced using a combination of spatiotemporal gap‑filling and Landsat–MODIS/VIIRS blending. Irrigation phenologies were first identified using Self‑Organising Maps (SOMs) applied to NDVI and ETa time series, and then mapped across the basin for all years using a supervised Pattern Recognition Neural Network (PRNN) (weighted Kappa = 0.91). Irrigation water use (IWUnet) was estimated per pixel using a monthly Thornthwaite–Mather soil water balance, separating green (rainfall-derived) and blue (irrigation-derived) ETa components. Validation was undertaken across multiple spatial scales using flux tower ETa, irrigation district annual reports, agricultural statistics, and MDB‑scale water accounting. Across most regions, both irrigated area and IWUnet exhibited high to moderate accuracy (typically R² > 0.8), with performance reflecting known spatial and temporal patterns in water availability and irrigation dynamics. This dataset provides the first multi-decadal, basin‑wide, high‑resolution record of irrigated extent and water use in the MDB and supports hydrological modelling, irrigation benchmarking, and long-term water resource assessment.