2.6.2.9 Limitations and conclusions

Summary

The groundwater MODFLOW model described in this product is designed for the specific purpose of delivering a probabilistic assessment of the impact of the additional coal resource development on water resources in the Clarence-Moreton bioregion. In its current form, the model is not suited to address any other water management questions without formal re-evaluation of the conceptualisation, parameterisation and boundary conditions. Unlike deterministic models, the stochastic results of this modelling cannot be fully characterised in a single number. Any evaluation or further use of parameter combinations derived in this work or predictions obtained should therefore always be based on their full posterior probability distribution.

The qualitative uncertainty analysis identified the data limitations that have the largest influence on the predictions. These data gaps present the greatest opportunities to reduce predictive uncertainty. The main opportunities lie in increasing the understanding and conceptualisation of the deeper layers, including the aquifer assignment, and in increasing the knowledge base of hydraulic properties of aquifers and aquitards, especially the vertical hydraulic conductivity and storage.

The current model has shown that the potential hydrological change due to coal resource development at model nodes can be deemed to be very minor with a very low probability of exceeding trigger thresholds specified in the NSW aquifer interference policy. Predictions of drawdown can inform the assessment of direct impacts on groundwater-dependent assets, such as groundwater-dependent ecosystems (ecological assets), or groundwater bores used for stock, irrigation and domestic purposes (economic assets).

Last updated:
11 July 2017
Thumbnail images of the Clarence-Moreton bioregion

Product Finalisation date

20 October 2016
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