干旱区生态环境知识资源中心(Arid): Using geochemistry to discern the patterns and timescales of groundwater recharge and mixing on floodplains in semi-arid regions

Arid

DOI	10.1016/j.jhydrol.2019.01.023
	Using geochemistry to discern the patterns and timescales of groundwater recharge and mixing on floodplains in semi-arid regions
	Cartwright, Ian 1; Werner, Adrian D.2; Woods, Juliette A.2,3
通讯作者	Cartwright, Ian
来源期刊	JOURNAL OF HYDROLOGY
ISSN	0022-1694
EISSN	1879-2707
出版年	2019
卷号	570 页码:612-622
英文摘要	Floodplains may alternate between discharge zones for regional groundwater and areas of recharge from river water during high-flow events. Understanding the mechanisms and timescales of recharge on floodplains is important for their management and for the protection of fragile ecosystems. The floodplains of the River Murray host important ecosystems, particularly remnant eucalypt forests that are vulnerable to changes in inundation, rising regional water tables, and salt accumulation. This study addresses floodplain recharge and groundwater mixing on the Pike and Katarapko floodplains of South Australia. At Pike,H- 3 activities of groundwater in the low hydraulic conductivity Coonambidgal Formation that crops out on the floodplain are similar to 0.25 TU, H-3 activities of groundwater in the underlying higher hydraulic conductivity Monoman Formation decrease from similar to 1 TU near the contact with the Coonambidgal Formation to < 0.02 TU at > 15 m depth. Groundwater C-14 activities are between 40 and 95 pMC but are less well correlated with depth. The H-3 or C-14 activities do not vary systematically with distance from the surface water channels on the floodplains. These observations imply that groundwater recharge at Pike is dominantly through the floodplain rather than through the channel banks. In contrast to the regional groundwater where total dissolved solids (TDS) concentrations are commonly > 35,000 mg/L, the TDS of groundwater on the floodplain is locally < 500 mg/L. A correlation between H-3 activities and TDS and the presence of groundwater with relatively low C-14 activities but above detection H-3 activities implies that recently recharged waters have mixed with regional groundwater in the floodplain sediments. The H-3 activities in these mixed waters implies that mixing occurs over a few years. By contrast, at Katarapko, the highest 3 H activities in the Monoman Formation groundwater (up to 2.35 TU) are closer to the Murray River, implying that recharge through the bank may occur. These contrasting patterns of recharge probably reflect local topographic controls. Understanding the recharge-discharge relationships are vital for managing proposed floodplain inundation programs aimed at improving ecosystem health.
英文关键词	Groundwater geochemistry Recharge Residence times Riverine environments Floodplain ecosystems
类型	Article
语种	英语
国家	Australia
开放获取类型	Green Accepted
收录类别	SCI-E
WOS记录号	WOS:000460709400050
WOS关键词	SURFACE WATER INTERACTIONS ; MEAN TRANSIT-TIME ; MURRAY BASIN ; RIVER MURRAY ; ENVIRONMENTAL ISOTOPES ; LAND-USE ; SALINITY ; TRITIUM ; SYSTEM ; AGE
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/2XILL650/217135
作者单位	1.Monash Univ, Sch Earth Atmosphere & Environm, Clayton, Vic 3800, Australia; 2.Flinders Univ S Australia, Coll Sci & Engn, GPO Box 2100, Adelaide, SA 5001, Australia; 3.Dept Environm & Water, Adelaide, SA, Australia
推荐引用方式 GB/T 7714	Cartwright, Ian,Werner, Adrian D.,Woods, Juliette A.. Using geochemistry to discern the patterns and timescales of groundwater recharge and mixing on floodplains in semi-arid regions[J],2019,570:612-622.
APA	Cartwright, Ian,Werner, Adrian D.,&Woods, Juliette A..(2019).Using geochemistry to discern the patterns and timescales of groundwater recharge and mixing on floodplains in semi-arid regions.JOURNAL OF HYDROLOGY,570,612-622.
MLA	Cartwright, Ian,et al."Using geochemistry to discern the patterns and timescales of groundwater recharge and mixing on floodplains in semi-arid regions".JOURNAL OF HYDROLOGY 570(2019):612-622.