2.6.1.3.1 Spatial and temporal dimensions

The Hunter subregion comprises two separate river basins (Figure 4). The Hunter River drains the majority of the subregion, while numerous small rivers drain a coastal section of the subregion that is known as the Macquarie-Tuggerah lakes basin. The modelling domain for surface water modelling in the Hunter subregion includes part of the Hunter river basin and part of the Macquarie-Tuggerah lakes basin.

In the Hunter river basin the modelling domain consists of the catchment of the Hunter River above Greta. Greta is chosen as the lower limit for the modelling domain because it marks the approximate point in the river below which tidal influences become important. The catchment of the Hunter River above Greta covers an area of about 17,600 km2.

The part of the Macquarie-Tuggerah lakes basin that is included in the modelling domain is the catchment of the Wyong River above Wyong. This point also represents the approximate tidal limit and is about 8 km above the location where the Wyong River discharges into Tuggerah Lake. Other parts of the Macquarie-Tuggerah lakes basin are not included because estimates of baseflow changes from groundwater drawdown are not available. The catchment of the Wyong River above Wyong covers an area of about 400 km2.

Both the baseline and coal resource development pathway (CRDP) include simulations from 2013 to 2102. However, for both, the period from 1983 to 2012 is also modelled and acts as an extended model spin-up period.

Both surface water models, the Australian Water Resources Assessment (AWRA) landscape model (AWRA-L) and the AWRA river model (AWRA-R), operate on a daily time step. AWRA-L uses a spatial grid resolution of 0.05 x 0.05 degrees (approximately 5 x 5 km), while the smallest spatial unit in AWRA-R is the subcatchment, with size dictated by the location of model nodes. Unless indicated otherwise in this section, surface water modelling in the Hunter subregion follows the methodology set out in companion submethodology M06 (as listed in Table 1) for surface water modelling (Viney, 2016).

Last updated:
18 January 2019
Thumbnail of the Hunter subregion

Product Finalisation date

2018

ASSESSMENT