The Hunter subregion has a long history of mining. There are 42 baseline mines and 22 additional coal resource developments that have been represented in the numerical modelling. To quantify the effects that these developments have on regional-scale hydrology requires a significant investment of time, in terms of obtaining the relevant digital data from the mines and state agencies that produce or hold these data, sifting through the large number of environmental assessment documents produced by mining companies to extract relevant bits of information to inform the modelling, digitising maps and remotely sensed imagery to obtain footprint areas, undertaking analyses to determine patterns of change and rules for representing hydrological changes in the models and so on. Excluding those coal resource developments identified in companion product 2.3 (conceptual modelling) for the Hunter subregion (Dawes et al., 2018) as having insufficient data available to model, data have been obtained to represent the hydrological effect of every modelled mine. Thus gaps in the context of the mine water management data used in the numerical modelling relate to opportunities to improve the input datasets and better represent processes in the model beyond what was possible with the time and resources that were available. The following are where uncertainties could be reduced through acquiring more data and/or making better use of the available data:

  • Mine footprint data – a range of sources of data and methods for defining areas where hydrology is affected by mining were relied upon, resulting in a dataset with considerable uncertainty in extent of areas affected hydrologically by mining over time. There is potential to improve footprint time series data through closer collaboration with mining companies and state agencies that have mining data to access more data, to better understand the available data (e.g. what it represents, purpose, provenance), to undertake quality assurance (e.g. method of mapping, scale of mapping) and to collate data from different sources into a combined dataset based on the foregoing.
  • Final voids – use actual data from all sites with open-cut operations to define the final voids, rather than estimating from mines with data.
  • Analysis of modelled flow rates (undertaken to determine water licence entitlement volumes) and actual flow rates data to determine extraction rates relative to licensed volume and drivers of use rates (e.g. climate).

Companion product 2.6.1 (surface water numerical modelling; Zhang et al. (2018)) and companion product 2.6.2 (groundwater numerical modelling; Herron et al. (2018)) for the Hunter subregion provide more details of the sources of uncertainty in representing the hydrological effects of coal resource development and implications for modelling results.

Last updated:
18 January 2019
Thumbnail of the Hunter subregion

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