It will develop and evaluate new tools and techniques to assess the status of GAB groundwater resources to support responsible management of Basin water resources. Frontier Economics. The atlas presents a compilation of maps documenting some of the key regional geological, hydrogeological and hydrochemical aspects of the GAB.
It provides insights into the current understanding of the regional geometry and physical characteristics of the rocks and water contained within this vast groundwater basin and baseline information against which future changes can be assessed.
Since these projects, new information has led to some of the concepts and interpretations being revised or refined for this atlas. Two key pieces of new work that are presented in this atlas are the up to date interpretations of the extent and thickness of the major aquifers and aquitards and the basin-wide perspective of the variation of water chemistry found within the major aquifers.
During a time when much of what is now inland Australia was below sea level, the sandstone was then covered by a layer of marine sedimentary rock shortly afterwards, which formed a confining layer - thus trapping water in the sandstone aquifer. The eastern edge of the basin was uplifted when the Great Dividing Range formed. The other side was created from the landforms of the Central Eastern Lowlands and the Great Western Plateau to the west.
The impermeable rocks confine the aquifers, causing the groundwater to become pressurised. In most areas the water is under sufficient pressure to provide a flowing source once it rises to the surface through artesian bores and natural springs. Most recharge water enters the rock formations from relatively high ground near the eastern edge of the basin in Queensland and New South Wales and very gradually flows towards the south and west.
A much smaller amount enters along the western margin in arid central Australia, flowing to the south and east. Because the sandstones are permeable, water gradually makes its way through the pores between the sand grains, flowing at a rate of one to five metres per year. Discharge water eventually exits through a number of springs and seeps, mostly in the southern part of the basin. Continued extraction of groundwater from the Basin requires continued measurement of the groundwater levels.
Similar to trying to predict the weather, careful and continued observation will help us improve predicting how the GAB will respond to future conditions. The assessment and its products should help better inform government policy, community and industry decision making. For example, it may be used to guide future targeted bore monitoring by identifying where potential stresses in the Basin might occur.
It will also allow for more informed assessments of development proposals by state and Australian government regulators. Festival of Social Science — Aberdeen, Aberdeenshire. Edition: Available editions United Kingdom.
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