National data for Australia's ecosystem services: groundwater fraction of the total irrigation water use by state/territory, Australia: 2002-03 to 2023-24

This collection was developed primarily to support national ecosystem accounting. It provides annual estimates of the groundwater fraction of irrigation water use for each Australian state and territory. The reported series covers financial years 2002–03 to 2023–24, with each reporting year defined from 1 July to 30 June.

The groundwater fraction is defined as the proportion of irrigation water use sourced from groundwater within a given state or territory in a given financial year. Estimates are reported as dimensionless fractions (0–1) and include associated standard errors to indicate uncertainty.

The primary estimates were generated using state- and territory-specific statistical models calibrated with data from 2010–11 to 2020–21 and then applied to reconstruct the full 2002–03 to 2023–24 series. Additional estimates based on temporal-block cross-validation (Temporal-block CV) and leave-one-out cross-validation (LOOCV) were generated using model building over 2005–06 to 2020–21 and are included for methodological comparison and robustness assessment.

The collection is provided as an Excel workbook with three worksheets:

Estimated groundwater fraction of irrigation water use by state/territory, Australia, 2002–03 to 2023–24
Primary model-based estimates.
Estimated groundwater fraction of irrigation water use by state/territory, Australia, 2005–06 to 2020–21 using the temporal-block cross-validation method
Estimates derived using temporal-block cross-validation (Temporal-block CV).
Estimated groundwater fraction of irrigation water use by state/territory, Australia, 2005–06 to 2020–21 using the leave-one-out cross-validation method
Estimates derived using leave-one-out cross-validation (LOOCV).