Breadcrumb

2.6.1 Surface water numerical modelling

The products on surface water numerical modelling present potential changes in surface water due to coal resource development in bioregions or subregions. The products also describe uncertainties in model outputs.

Surface water modelling predicts the difference between hydrological characteristics in two potential futures:

  • baseline coal resource development (baseline): a future that includes all coal mines and coal seam gas fields that were commercially producing as at December 2012
  • coal resource development pathway (CRDP): a future that includes all coal mines and coal seam gas fields that are in the baseline as well as those that were expected to begin commercial production after December 2012.

The difference in results for these possible futures is due to the additional coal resource development –all coal mines and coal seam gas fields, including expansions of baseline operations, that were expected to begin commercial production after December 2012.

Surface water models were drawn from the Australian Water Resource Assessment (AWRA) modelling suite, which includes the landscape model AWRA-L for streamflow prediction, and river systems model AWRA-R for river routing and management. The latter is only used in a subset of subregions or bioregions and the model selected depends on the nature of the river regulation and the availability of existing streamflow data.

Relationship to other products

Results from surface water numerical modelling are used as inputs for receptor impact modelling (product 2.7), where resulting changes to key characteristics in the landscape or water-dependent asset are estimated.

Predictions from surface water numerical modelling and receptor impact modelling are further considered in the impact and risk analysis (product 3-4), which examines the risks to and potential impacts on water resources and water-dependent assets due to coal seam gas or coal mining developments in a bioregion or subregion.