The uncertainty analysis includes quantitative uncertainty analysis to provide ensembles of the predicted change in hydrological response variables at the receptors as well as qualitative assessment of the effect of model assumptions on the prediction.

For each hydrological response variable, an ensemble of parameter combinations is selected from a large range of parameter combinations that result in an acceptable mismatch between historically observed hydrological response variables and simulated equivalents.

This ensemble of parameter combinations is used to calculate the absolute change, the relative change and the time to absolute change for each hydrological variable at each receptor.

A comprehensive sensitivity analysis is carried out to ensure that the parameters that can be constrained by the historical observations are ones the predictions are sensitive to.

In the qualitative uncertainty analysis the rationale behind the major assumptions and their effect on predictions is discussed and scored. The assumption deemed to have the largest effect on predictions is the implementation of the coal resource development pathway (CRDP). The numerical predictions are only valid for the open-cut coal mine footprints implemented in the model sequence, as modelling of impacts of coal seam gas (CSG) infrastructure on surface water were not modelled.

Last updated:
31 October 2018
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