Great Artesian Basin Groundwater recharge zones and whole of basin boundaries 2022

The<em> Great Artesian Basin (GAB) Groundwater Recharge Zones and Extent Boundary 2022</em> dataset provides Geoscience Australia’s latest interpretation of the extent of: ·  the GAB and its four component geological sub-basins – the Eromanga, Carpentaria, Surat and Clarence-Moreton basins; and ·  the GAB aquifer outcrop/subcrop areas that comprise the groundwater recharge zones of the GAB.<br>These datasets are an updated regional interpretation for mapping at approximately 1:1 000 000 to produce a broad scale overview, and examination of small areas by collecting extra data is most likely to produce results that differ from this regional interpretation.<br>The <em>GAB Groundwater Recharge Zones and Extent Boundary 2022</em> data compilation comprises the following:1.    GAB extent boundaries 2022 ·  GAB_Basin_2022 – polygon covering the extent of the of the Great Artesian Basin as defined by Geoscience Australia ·  GAB_SubBasins_2022 – polygon dataset defining the extents of the component geological sub-basins of the GAB: Eromanga Basin, Surat Basin, Carpentaria Basin and Clarence-Moreton ·  GAB_Basin_BoundarySource_2022 – line dataset containing information on the different data sources used to define the boundary of the GAB and sub-basin subdivisions.<br>2.    GAB Groundwater Recharge Zones 2022 ·  GAB_RechargeZones_2022 – polygon dataset depicting areas of recharge within the GAB ·  GAB_RechargeZones_2022.lyr – group layer file containing: ·  GAB_RechargeZones_2022_geology (symbolised by geology type) ·  GAB_RechargeZones_2022_aquifer (symbolised by GAB aquifer) ·  GAB_RechargeZones_2022_cover (symbolised by qualitative cover classes) ·  GAB_RechargeZones_2022_source (symbolised by datasets utilised to determine recharge zones),  1.   Great Artesian Boundaries Basin boundaries<br>The GAB boundary follows the geological margins of its four component sub-basins – the Eromanga, Carpentaria, Surat and Clarence-Moreton sub-basins (GAB_SubBasins_2022). In certain areas the boundary diverges from these geological basin margins and dissects outcropping geological units, delineating externally-draining groundwater regions not flowing into the GAB. In these areas the boundary is based on interpreted groundwater divides, indicated by topographic divides, derived from the 1 second SRTM (Gallant et al. 2011). 2. Groundwater recharge zone boundaries<br>This dataset contains the mapped outcrop and subcrop extents of the regional aquifers of the GAB that constitute the groundwater recharge zones of the GAB. <br>Groundwater recharge zones delineate areas where water infiltrates the aquifers of the GAB. The spatial extents of the recharge zones are defined by a combination of the outcrop extents of aquifer units, and interpolation between outcrops, in cases where the units are covered by a veneer of unconsolidated deposits.<br>The numerous geological units that comprise the aquifers of the GAB are grouped into the following regional aquifers (in age order):·         Winton-Mackunda Aquifer and Equivalents·         Cadna-owie – Hooray Aquifer and Equivalents·         Adori-Springbok Aquifer·         Birkhead Formation partial aquifer·         Hutton Aquifer and Equivalents·         Boxvale Sandstone Member Aquifer·         Precipice Aquifer and Equivalents<br>The Groundwater recharge zones have been modified from Ransley et al., 2015 to incorporate revised geology mapping for QLD and NSW (refer to metadata available with download).<br>References:Gallant, J., Wilson, N., Dowling, T., Read, A., Inskeep, C. 2011. SRTM-derived 1 Second Digital Elevation Models Version 1.0. Record 1. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/72759<br>Ransley, T., Radke, B., Kellett, J., Bell, J., Stewart, G 2015. Great Artesian Basin - Groundwater/aquifer recharge zones. Geoscience Australia, Canberra. http://pid.geoscience.gov.au/dataset/ga/81687