Background and context

The surface water numerical modelling in bioregional assessments (BAs) has a specific objective: to probabilistically evaluate potential hydrological change caused by the coal resource development pathway (CRDP) relative to the baseline at specified locations in the subregion. Outputs from the surface water modelling are used to inform both the impact and risk analysis (reported in product 3-4) and receptor impact modelling (product 2.7) to facilitate evaluation of the cumulative impacts of coal resource development on water-dependent assets (including ecological, economic and sociocultural assets).

To evaluate these impacts probabilistically large ensembles of predictions are generated using a range of model parameter sets. The range of parameters reflects the natural variability of the system thus covering uncertainty in the understanding of the system. During the uncertainty analysis, these parameter combinations are filtered in such a way that only those that are consistent with the available observations and the understanding of the system are used to generate the ensemble of predictions. The details are documented in companion submethodology M09 (as listed in Table 1) for propagating uncertainty through models (Peeters et al., 2016).

It is not possible to capture all uncertainty of the understanding of the system in the parameterisation of the numerical models, so it is inevitable that there will be a number of assumptions. These assumptions are introduced and briefly discussed in Section on model development. The uncertainty analysis in Section further provides a systematic and comprehensive discussion of these assumptions. This discussion focuses on the rationale behind the assumptions and the effect on the predictions. The latter is crucial in justifying assumptions.

Last updated:
6 December 2018
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