干旱区生态环境知识资源中心(Arid): Characterization of groundwater types and residence times in the Verlorenvlei catchment, South Africa to constrain recharge dynamics and hydrological resilience

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DOI	10.1016/j.jhydrol.2022.128280
	Characterization of groundwater types and residence times in the Verlorenvlei catchment, South Africa to constrain recharge dynamics and hydrological resilience
	Miller, J. A.; Turner, K. B.; Watson, A.; van Rooyen, J.; Molnar, M.; Turi, M.; Palcsu, L.
通讯作者	Miller, JA
来源期刊	JOURNAL OF HYDROLOGY
ISSN	0022-1694
EISSN	1879-2707
出版年	2022
卷号	613
英文摘要	The Verlorenvlei catchment on the west coast of South Africa is a semi-arid region that is growing progressively more reliant on groundwater due to increased variability in precipitation and increasing agricultural produc-tivity. The groundwater systems have been put under additional stress given the recent 2015-2017 El Nino similar to system that led to drought conditions along the west coast of South Africa. This increased reliance puts the natural environment and human dependence on groundwater into direct conflict. Groundwater was sampled for delta 18O, delta 2H, delta 13C, 14C, 3H and 3H/3He ratios in addition to cation and anion concentrations from seventeen production boreholes and two springs in the catchment. Residence times were estimated using tritium and radiocarbon, and in the case of the latter, the Pearson Model has been used to correct for possible carbonate dissolution. Hydrochemistry and residence times of groundwater in the Verlorenvlei catchment have successfully been used to distinguish between the primary-porosity alluvial aquifer, the secondary-porosity Malmesbury shale aquifer (MG) and the fractured rock aquifers associated with the Table Mountain Group (TMG). Ground-water mixing has been identified within the catchment and this plays an important role in the variation in groundwater chemistry and residence time between the aquifer systems. The discrepancy between the calculated radiocarbon and 3H/3He ages in the TMG and alluvial aquifers has been evaluated using a lumped parameter model that confirms that the TMG is strongly dominated by young groundwaters. Young 3H/3He residence times calculated for groundwater in the TMG (34-57 years) and alluvial aquifers (34-47 years) implies that these systems are most susceptible to reduced groundwater recharge. Given the interconnected nature of the aquifer systems, reduced recharge rates into the TMG aquifer will decrease groundwater flow to both the alluvial and MG aquifer and this will impact the long-term sustainability of the RAMSAR listed Verlorenvlei estuarine lake and wetlands at the catchment outlet. Future residence time studies should consider using a lumped parameter model (LPM) to calculate the age distribution of groundwater in these aquifers as this would provide additional insight into the sustainability of the groundwater systems.
英文关键词	Groundwater residence times Verlorenvlei Table Mountain Group Aquifer Groundwater mixing Tritogenic Helium Radiocarbon dating
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000862505600003
WOS关键词	WESTERN SALDANIA BELT ; CLIMATE-CHANGE ; NORTHERN SANDVELD ; STABLE-ISOTOPE ; TRANSIT-TIME ; WATER ; CHALLENGES ; AQUIFER ; TRITIUM ; IMPACT
WOS类目	Engineering, Civil ; Geosciences, Multidisciplinary ; Water Resources
WOS研究方向	Engineering ; Geology ; Water Resources
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/393505
推荐引用方式 GB/T 7714	Miller, J. A.,Turner, K. B.,Watson, A.,et al. Characterization of groundwater types and residence times in the Verlorenvlei catchment, South Africa to constrain recharge dynamics and hydrological resilience[J],2022,613.
APA	Miller, J. A..,Turner, K. B..,Watson, A..,van Rooyen, J..,Molnar, M..,...&Palcsu, L..(2022).Characterization of groundwater types and residence times in the Verlorenvlei catchment, South Africa to constrain recharge dynamics and hydrological resilience.JOURNAL OF HYDROLOGY,613.
MLA	Miller, J. A.,et al."Characterization of groundwater types and residence times in the Verlorenvlei catchment, South Africa to constrain recharge dynamics and hydrological resilience".JOURNAL OF HYDROLOGY 613(2022).