Significance of the connection between bedrock, alluvium and streams: a spatial and temporal hydrogeological and hydrogeochemical assessment from Queensland, Australia

Simple item page
dc.contributor.authorRaiber, Men_AU
dc.contributor.authorLewis, Sen_AU
dc.contributor.authorCendón, DIen_AU
dc.contributor.authorCui, Ten_AU
dc.contributor.authorCox, MEen_AU
dc.contributor.authorGilfedder, Men_AU
dc.contributor.authorRassam, DWen_AU
dc.date.accessioned2021-12-01T22:34:48Zen_AU
dc.date.available2021-12-01T22:34:48Zen_AU
dc.date.issued2019-02en_AU
dc.date.statistics2020-10-14en_AU
dc.description.abstractCatchment-scale hydrological and hydrogeological investigations commonly conclude by finding that particular stream reaches are either gaining or losing; they also often assume that the influence of bedrock aquifers on catchment water balances and water quality is insignificant. However, in many cases, such broad findings are likely to oversimplify the spatial and temporal complexity of the connections between the different hydrological system components, particularly in regions dominated by cycles of droughts and flooding. From a modelling perspective, such oversimplifications can have serious implications on the process of identifying the magnitude and direction of the exchange fluxes between the surface and groundwater systems. In this study, we use 3D geological modelling and historic water chemistry and hydraulic records to identify the origins of groundwater at different locations in the alluvium and along the course of streams in the Lockyer Valley (Queensland, Australia), a catchment impacted by a severe drought (‘Millennium Drought’) from 1998 to 2009, followed by extensive flooding in 2011. We also demonstrate how discharge from the sub-alluvial regional-scale volcanic and sedimentary bedrock influences the water balance and water quality of the alluvium and streams. The investigation of aquifer geometry via development of a three-dimensional geological model combined with an assessment of hydraulic data provided important insights on groundwater flow paths and helped to identify areas where bedrock aquifers interact with shallow alluvial aquifers and streams. Multivariate statistical techniques were then applied as an additional line of evidence to groundwater and surface water hydrochemical data from large historical datasets. This confirmed that most sub-catchments within the Lockyer Valley have distinct water chemistry patterns, which result from mixing of different water sources, including discharge from the sub-alluvial bedrock. Importantly, in addition to the observed spatial variability, time-series hydrochemical groundwater and surface water data further demonstrated that the hydraulic connection between alluvial aquifers, streams and sub-alluvial bedrock aquifers is temporally dynamic with very significant changes occurring at the transition from normal to drought conditions and following flooding, affecting both catchment water quality and water balances. Crown Copyright © 2018 Published by Elsevier B.V.en_AU
dc.identifier.citationRaiber, M., Lewis, S., Cendón, D. I., Cui, T., Cox, M. E., Gilfedder, M., & Rassam, D. W. (2019). Significance of the connection between bedrock, alluvium and streams: a spatial and temporal hydrogeological and hydrogeochemical assessment from Queensland, Australia. Journal of Hydrology, 569, 666-684. doi:10.1016/j.jhydrol.2018.12.020en_AU
dc.identifier.issn0022-1694en_AU
dc.identifier.journaltitleJournal of Hydrologyen_AU
dc.identifier.pagination666-684en_AU
dc.identifier.urihttps://doi.org/10.1016/j.jhydrol.2018.12.020en_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/12317en_AU
dc.identifier.volume569en_AU
dc.language.isoenen_AU
dc.publisherElsevier B. V.en_AU
dc.subjectAquifersen_AU
dc.subjectInteractionsen_AU
dc.subjectGround wateren_AU
dc.subjectSurface watersen_AU
dc.subjectQueenslanden_AU
dc.subjectAustraliaen_AU
dc.subjectGeologic modelsen_AU
dc.subjectGeochemistryen_AU
dc.subjectDataen_AU
dc.subjectFloodsen_AU
dc.subjectDroughtsen_AU
dc.titleSignificance of the connection between bedrock, alluvium and streams: a spatial and temporal hydrogeological and hydrogeochemical assessment from Queensland, Australiaen_AU
dc.typeJournal Articleen_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
1-s2.0-S0022169418309697-main.pdf
Size:
6.71 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles