2.5.1 Methods


The groundwater balance analysis was conducted for the entire groundwater model domain, which covers an area of 8230 km2. The groundwater balances comprise recharge, boundary flux, discharge to surface water, mining pumping, non-mining groundwater extractions, and change in storage water balance terms. The surface water balance analysis covers an area of 2942 km2 and is reported at four locations: the Richmond River above Casino, the Richmond River above Kyogle, Shannon Brook above Yorklea and Eden Creek. The surface water balances comprise rainfall, surface water outflow, and losses (including evapotranspiration and water extractions). The groundwater and surface water balances are reported for three 30-year periods (2013 to 2042, 2043 to 2072 and 2073 to 2102) for both the baseline and the coal resource development pathway (CRDP). The analysis was carried out based on 30 model realisations chosen from a total of 3877 successful simulations conducted for the sensitivity analysis reported in companion product 2.6.2 (groundwater numerical modelling) for the Clarence Moreton bioregion (Cui et al., 2016).

The water balance assessment presents a quantitative water balance for the Clarence-Moreton bioregion for both the baseline and the coal resource development pathway (CRDP). It was conducted under the guidance of companion submethodology M07 (Crosbie et al., 2016). The water balance components were derived from the outputs of the surface water modelling and the groundwater modelling that are reported in companion products 2.6.1 and 2.6.2 for the Clarence-Moreton bioregion (Gilfedder et al., 2016; Cui et al., 2016), respectively. See Section and Section in these products for caveats and limitations associated with the information.

Last updated:
11 July 2017