2.1.3 Hydrogeology and groundwater quality


Summary

Datasets used in the groundwater modelling are identified. They include regolith depth, extent of Hunter alluvium, depth to watertable, recharge and hydraulic conductivity datasets.

Sources of data are provided, as well as the methods used to analyse and generate new datasets to inform the modelling. A detailed description of the data analysis and methods to create a recharge surface for the Hunter subregion is provided.

Depth to watertable data from Hunter subregion bores are generally poor, with many bores having only one or two measurements, as well as lack of supporting information and negligible quality assurance. Depth to watertable data are needed to constrain groundwater model results and to produce an interpolated depth to watertable surface for the subregion; however, the lack of confidence in the underpinning data results in increasing uncertainty in derived products.

This section describes some of the datasets that have been used to inform the groundwater modelling of the Hunter subregion. Some are used directly (this includes clipping to the required extent for modelling and/or extracting a specific attribute), whereas others have been derived from multiple data sources for modelling purposes. Not all datasets are reported here. Data used in calibration of groundwater models are reported in companion product 2.6.2 for the Hunter subregion (Herron et al., 2018). The geological model is described in Section 2.1.2 of this product.

Table 6 lists the key datasets used to construct the groundwater model and where they are reported within the Hunter subregion suite of products. The datasets are classified as either ‘source datasets’ (i.e. pre-existing datasets sourced from outside the Bioregional Assessment Programme, but including data sourced from the Programme partner organisations) or ‘derived datasets’ that have been generated by the Programme for groundwater modelling purposes in the Hunter subregion. Details of source datasets and data processing to represent the baseline and additional coal resource developments in the modelling simulations are provided in Section 2.1.6 of this product.

No groundwater quality data are used in the groundwater modelling.

Table 6 Key datasets used for groundwater modelling for the Hunter subregion


Dataset

Source or Derived

Dataset

Details in

Digital elevation model

Derived

Bioregional Assessment Programme (Dataset 1)

Section 2.1.3.2.2

Vegetation height

Source

Caltech/JPL (Dataset 2)

Section 2.1.3.2.2

Geological model

Derived

Bioregional Assessment Programme (Dataset 3)

Section 2.1.2

Recharge

Derived

Bioregional Assessment Programme (Dataset 4)

Section 2.1.3.2.1 and Section 2.1.3.2.1

Regolith depth

Source

CSIRO (Dataset 5)

Section 2.1.3.1.1

Alluvium extent

Derived

Bioregional Assessment Programme (Dataset 6), extracted from Geoscience Australia (Dataset 7)

Section 2.1.3.1.1

Depth to watertable

Derived

Bioregional Assessment Programme (Dataset 8)

Section 2.1.3.1.3

Hydraulic conductivity

Derived

Bioregional Assessment Programme (Dataset 9)

Section 2.1.3.2.2

River network

Derived

Bioregional Assessment Programme (Dataset 10)

Product 2.6.2 Groundwater numerical modelling (Herron et al., 2018)

Groundwater extractions (non-mining)

Source

NSW Department of Primary Industries, NSW Office of Water (Dataset 11)

Product 2.6.2 Groundwater numerical modelling (Herron et al., 2018);

Product 1.5 Current water account for the Hunter subregion (Zhang et al., 2016)

Potential evapotranspiration

Derived

Bioregional Assessment Programme (Dataset 12)

Product 2.6.2 Groundwater numerical modelling (Herron et al., 2018)

Section 2.1.3.1 provides details of observed (source) data that have been used for groundwater modelling. The statistical analysis and interpolation section (Section 2.1.3.2) describes the methods for deriving datasets for input into the groundwater model from existing data.

Last updated:
18 January 2019
Thumbnail of the Hunter subregion

Product Finalisation date

2018

ASSESSMENT