~(14)C and ~(36)Cl as indicators of groundwater flow, Bland Catchment, NSW

摘要

Multi-component geochemical tracers together with physical parameters were used to identify the processes controlling groundwater chemistry and flow in the Bland Catchment, NSW Australia. These results are here combined with ~(36)Cl and ~(14)C data to provide a better understanding of the Bland and Lachlan hydrogeological systems for improved groundwater management. In the Lake Cowal region ~(14)C corrected ages indicate that groundwater flow in the Lachlan Formation has not always been consistent with current groundwater flow directions. ~(14)C data also show that the reversal of groundwater flow from the Lachlan Valley to the Bland Catchment has persisted for thousands of years and is not a direct effect of current irrigation practices. ~(36)Cl results support Cl/Br ratios and δ~(18)O and δ~2H data, showing evaporation in groundwater in the Cowra Formation aquifer in the north center of the catchment.