This grid dataset is an estimation of the relative surface potential for recharge within the Nulla Basalt Province. This process combined numerous factors together as to highlight the areas likely to have higher potential for recharge to occur. Soil permeability and surface geology are the primary inputs. Vegetation and slope were excluded from consideration, as these were considered to add too much complexity. Furthermore, this model does not include rainfall intensity – although this is known to vary spatially through average rainfall grids, this model is a depiction of the ground ability for recharge to occur should a significant rainfall event occur in each location. The relative surface potential recharge presented is estimated through a combination of soil and geological factors, weighting regions that are considered likely to have greater potential for recharge (e.g. younger basalts, vent-proximal facies, and highly permeable soils). Near-surface permeability of soil layers has been considered as a quantified input to the ability for water to infiltrate soil strata. It was hypothesised that locations proximal to volcanic vents would be preferential recharge sites, due to deeply penetrative columnar jointing. This suggestion is based on observations in South Iceland, where fully-penetrating columnar joint sets are more prevalent in proximal facies compared to distal facies in South Iceland (Bergh & Sigvaldson 1991). To incorporate this concept, preferential recharge sites are assumed to be within the polygons of vent-proximal facies as derived from detailed geological mapping datasets. Remaining geology has been categorised to provide higher potential recharge through younger lava flows. As such, a ranking between geological units has been used to provide the variation in potential recharge estimates. <b>Reference</b> Bergh, S. G., & Sigvaldason, G. E. (1991). Pleistocene mass-flow deposits of basaltic hyaloclastite on a shallow submarine shelf, South Iceland. Bulletin of Volcanology, 53(8), 597-611. doi:10.1007/bf00493688

Porosity and permeability data form part of Geoscience Australia’s Reservoir, Facies and Shows (RESFACS) database, which contains depth-based information regarding porosity and permeability measured or interpreted from core, sidewall core and well-log analysis of rocks intersected by offshore petroleum wells. Porosity and permeability are rock properties related to the number, size, and connectivity of openings in the rock. More specifically, porosity of a rock is a measure of its ability to hold a fluid within pore-spaces and the permeability is a measure of the ease of flow of a fluid through a porous solid. Data entered into the porosity and permeability tables are primarily sourced from the Basic and Interpretive volumes of Well Completion Reports (WCR) provided by the petroleum industry to the Commonwealth under the Offshore Petroleum and Greenhouse Gas Storage Act (OPGGSA) 2006 and the previous Petroleum (submerged Lands) Act (PSLA) 1967. Data is also sourced from sedimentologic evaluations and petrophysical studies by Geoscience Australia and its predecessor organisations, the Australian Geological Survey Organisation (AGSO) and the Bureau of Mineral Resources (BMR), as well as from state and territory geological organisations, and scientific publications. The database structure has evolved over time and will keep changing as different types of relevant data become available and the delivery platform changes. Data hosted within Geoscience Australia’s Oracle petroleum wells database was initially delivered through the Petroleum Wells web page, http://dbforms.ga.gov.au/www/npm.well.search, which is in the process of being decommissioned . The porosity and permeability data will now be available to view and download through the Geoscience Australia Portal Core, https://portal.ga.gov.au/. Use Porosity and Permeability as your search term to find the relevant data.

This web service provides access to groundwater raster products for the Upper Burdekin region, including: inferred relative groundwater recharge potential derived from weightings assigned to qualitative estimates of relative permeability based on mapped soil type and surface geology; Normalised Difference Vegetation Index (NDVI) used to map vegetation with potential access to groundwater in the basalt provinces, and; base surfaces of basalt inferred from sparse available data.

This web service provides access to groundwater raster products for the Upper Burdekin region, including: inferred relative groundwater recharge potential derived from weightings assigned to qualitative estimates of relative permeability based on mapped soil type and surface geology; Normalised Difference Vegetation Index (NDVI) used to map vegetation with potential access to groundwater in the basalt provinces, and; base surfaces of basalt inferred from sparse available data.

This web service provides access to groundwater raster products for the Upper Burdekin region, including: inferred relative groundwater recharge potential derived from weightings assigned to qualitative estimates of relative permeability based on mapped soil type and surface geology; Normalised Difference Vegetation Index (NDVI) used to map vegetation with potential access to groundwater in the basalt provinces, and; base surfaces of basalt inferred from sparse available data.

This grid dataset is an estimation of the relative surface potential for recharge within the McBride Basalt Province. This process combined numerous factors together as to highlight the areas likely to have higher potential for recharge to occur. Soil permeability and surface geology are the primary inputs. Vegetation and slope were excluded from consideration, as these were considered to add too much complexity. Furthermore, this model does not include rainfall intensity – although this is known to vary spatially through average rainfall grids, this model is a depiction of the ground ability for recharge to occur should a significant rainfall event occur in each location. The relative surface potential recharge presented is estimated through a combination of soil and geological factors, weighting regions that are considered likely to have greater potential for recharge (e.g. younger basalts, vent-proximal facies, and highly permeable soils). Near-surface permeability of soil layers has been considered as a quantified input to the ability for water to infiltrate soil strata. It was hypothesised that locations proximal to volcanic vents would be preferential recharge sites, due to deeply penetrative columnar jointing. This suggestion is based on observations in South Iceland, where fully-penetrating columnar joint sets are more prevalent in proximal facies compared to distal facies in South Iceland (Bergh & Sigvaldson 1991). To incorporate this concept, preferential recharge sites are assumed to be within the polygons of vent-proximal facies as derived from detailed geological mapping datasets. Remaining geology has been categorised to provide higher potential recharge through younger lava flows. As such, a ranking between geological units has been used to provide the variation in potential recharge estimates. <b>References</b> Bergh, S. G., & Sigvaldason, G. E. (1991). Pleistocene mass-flow deposits of basaltic hyaloclastite on a shallow submarine shelf, South Iceland. Bulletin of Volcanology, 53(8), 597-611. doi:10.1007/bf00493688