Effects of Future Increases in Tidal Flooding on Salinity and Groundwater Dynamics in Coastal Aquifers DOI Creative Commons
James W. Heiss,

Bryce Mase,

Chengji Shen

et al.

Water Resources Research, Journal Year: 2022, Volume and Issue: 58(12)

Published: Dec. 1, 2022

Abstract Future increases in the frequency of tidal flooding due to sea level rise (SLR) are likely affect pore water salinities coastal aquifers. In this study, we investigate impact increased on salinity and flow dynamics aquifers using numerical variable‐density variably‐saturated groundwater salt transport models. Short (sub‐daily) long (decadal) period tides combined with SLR projections drive continuous 80‐year models transport. Results show that encroaching intertidal zones lead both periodic long‐term vertical salinization upper aquifer. Salinization aquifer forces lower interface seaward, even under SLR. System controlled by interplay between forcing associated perigean spring 18.6‐year lunar nodal cycle. Periodic substantially enhances saltwater‐freshwater mixing, resulting a 6‐ 10‐fold expansion mixing area across scenarios. The onset coincides extreme high levels from cycling constituent amplitudes. findings first demonstrate effects gradual short distributions, reveal competing influences saltwater intrusion. results have important implications for ocean chemical fluxes resources as intensifies worldwide.

Language: Английский

Submarine groundwater discharge impacts on coastal nutrient biogeochemistry DOI
Isaac R. Santos, Xiaogang Chen, Alanna L Lecher

et al.

Nature Reviews Earth & Environment, Journal Year: 2021, Volume and Issue: 2(5), P. 307 - 323

Published: March 30, 2021

Language: Английский

Citations

362
Coastal Hydrogeology DOI

Jimmy Jiao,

Vincent Post

Published: May 3, 2019

Water resources are of enormous societal and ecological importance. In coastal areas, they under ever greater pressure due to population growth, more affluent lifestyles, food production the growing tourism industry. Changes landscape, through urbanisation land reclamation, by natural processes such as climate change sea level rise, modify interaction between seawater groundwater put water at risk. This comprehensive volume covers both theory practice hydrogeology. It discusses hydrochemistry; submarine discharge; management; palaeo-hydrology; reclamation; rise; mathematical models variable-density flow. With its up-to-date coverage numerous case studies that illustrate practical implications, it is perfect for students, practitioners, managers researchers who wish develop an in-depth understanding topics relevant sustainably managing resources.

Language: Английский

Citations

94
Flow and Transport in Coastal Aquifer‐Aquitard Systems: Experimental and Numerical Analysis DOI Creative Commons
Jiaxu Zhang, Chunhui Lu, Chengji Shen

et al.

Water Resources Research, Journal Year: 2024, Volume and Issue: 60(4)

Published: April 1, 2024

Abstract Coastal aquifers are commonly layered, and thus, a clear understanding of groundwater flow salt transport in layered coastal is important for managing fresh groundwater. However, the influence leakage between adjacent on processes remains largely unknown where tides considered. This study used laboratory experiments numerical simulation to examine within tidal aquifer‐aquitard system (i.e., an unconfined aquifer underlain by semi‐confined aquifer, with intervening thin aquitard). The laboratory‐scale observations current first offshore aquifer. results close agreement, revealing that upward from into saltwater wedge overlying caused buoyant instabilities form. development freshwater fingers created complex saltwater‐freshwater mixing, leading mixed influx‐efflux patterns across sloping aquifer‐ocean interface. Compared non‐tidal conditions, forces reduced net increased horizontal toward sea, which turn extent higher rates both saline submarine discharge (SGD), tides, led lower ages These findings have implications unveiling characteristics seawater intrusion, SGD geochemical hotspots aquifers.

Language: Английский

Citations

9
Effects of boundary conditions and aquifer parameters on salinity distribution and mixing-controlled reactions in high-energy beach aquifers DOI Creative Commons
Rena Meyer, Janek Greskowiak, Stephan L. Seibert

et al.

Hydrology and earth system sciences, Journal Year: 2025, Volume and Issue: 29(5), P. 1469 - 1482

Published: March 18, 2025

Abstract. In high-energy beach aquifers fresh groundwater mixes with recirculating saltwater and biogeochemical reactions modify the composition of discharging to sea. Changing morphology, hydrodynamic forces, hydrogeological properties control density-driven flow transport processes that affect distribution chemical reactants. present study, modelling a generic 2-D cross-shore transect was conducted. Boundary conditions aquifer parameters were varied in systematic manner suite 24 cases. The objective investigate individual effects boundary on regime, salt distribution, potential for mixing-controlled system temporally variable morphology. Our results show changing morphology causes migration infiltration exfiltration locations along transect, leading transient patterns subsurface, thereby enhancing reactions. shape extent zone where potentially take place, as well spatiotemporal variability freshwater–saltwater interfaces, are most sensitive storm floods, hydraulic conductivity, dispersivity. study advances understanding subsurface flow, transport, mixing dynamic beneath beaches. These regulate nutrient fluxes coastal ecosystems.

Language: Английский

Citations

1
Solute transport influenced by unstable flow in beach aquifers DOI
Chengji Shen, Chenming Zhang, Jun Kong

et al.

Advances in Water Resources, Journal Year: 2019, Volume and Issue: 125, P. 68 - 81

Published: Jan. 29, 2019

Language: Английский

Citations

56
Influence of Tide‐Induced Unstable Flow on Seawater Intrusion and Submarine Groundwater Discharge DOI
Yunhai Fang, Tianyuan Zheng, Xilai Zheng

et al.

Water Resources Research, Journal Year: 2021, Volume and Issue: 57(4)

Published: April 1, 2021

Abstract Recent studies have confirmed the instability of tide‐induced upper saline plume (USP) in tidal beach aquifers. A systematic understanding how unstable USP contributes to groundwater flow and salinity distribution is still lacking. Here we used laboratory experiments numerical simulations examine responses submarine discharge (SGD) flow. The results revealed that changes physical forcing conditions (tides inland freshwater input) drove transition from stable states. Meanwhile, phase‐averaged SGD its components fluctuated over time, their oscillation amplitudes depended on conditions. There was a correlation between fluctuation water exchange across aquifer‐sea interface. fluxes interface under usually varied considerably time with lower frequency comparison extent seawater intrusion (SWI) measured by total salt mass stored aquifer also especially vibration tendency opposite sum circulation efflux. For coastal aquifers affected tides, SWI dominated efflux, followed input influx. These findings lay foundation for gaining better potential implications.

Language: Английский

Citations

54
A place for subterranean estuaries in the coastal zone DOI
Carlos Rocha, C. E. Robinson, Isaac R. Santos

et al.

Estuarine Coastal and Shelf Science, Journal Year: 2021, Volume and Issue: 250, P. 107167 - 107167

Published: Jan. 11, 2021

Language: Английский

Citations

51
Heterogeneity Affects Intertidal Flow Topology in Coastal Beach Aquifers DOI
Xiaolong Geng, Holly A. Michael, Michel C. Boufadel

et al.

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 47(17)

Published: Aug. 26, 2020

Abstract Intertidal aquifers are hotspots of biogeochemical cycling where nutrients and contaminants processed prior to discharge the ocean. The nature dynamic subsurface mixing zone is a critical control on mitigating reactions. Simulation density‐dependent, variably saturated flow salt transport incorporating realistic representations aquifer heterogeneity was conducted within Monte Carlo framework investigate influence nonuniform permeability intertidal groundwater dynamics. Results show that coupled with tides creates transient preferential paths zone, evolving multiple circulation cells fingering‐type salinity distributions. Due heterogeneity, strain‐dominated (intense mixing) vorticity‐dominated (low regions coexist at small spatial scales, their extent reaches peaks high tide low tide. Such topological characteristics reveal complex tempo‐spatial patterns for localized areas intensities, which have implications processing.

Language: Английский

Citations

50
Submarine groundwater discharge in response to the construction of subsurface physical barriers in coastal aquifers DOI
Yunhai Fang, Jiazhong Qian, Tianyuan Zheng

et al.

Journal of Hydrology, Journal Year: 2022, Volume and Issue: 617, P. 129010 - 129010

Published: Dec. 19, 2022

Language: Английский

Citations

30
Redox-zoning in high-energy subterranean estuaries as a function of storm floods, temperatures, seasonal groundwater recharge and morphodynamics DOI Creative Commons
Janek Greskowiak, Stephan L. Seibert, Vincent Post

et al.

Estuarine Coastal and Shelf Science, Journal Year: 2023, Volume and Issue: 290, P. 108418 - 108418

Published: June 24, 2023

Redox conditions are a major control for the concentrations and mass fluxes of water constituents, e.g., nutrients, metals organic molecules within subterranean estuaries (STE). Due to transient flow transport processes in STEs as well variable temperatures input redox reactants, zoning STE is believed be highly dynamic. In present study we analyzed individual combined effects storm floods, seasonal changes groundwater recharge rates, beach morphodynamics on STE. For this purpose, 2D cross-shore density-dependent reactive model was set up representing aquifer exposed high-mesotidal medium-to high-energy wave conditions, floods. The simulation results show that under given dynamics may occur down depth 20 m. Morphodynamics appear most important factor transience zones compared other factors. Seasonal meteoric rates least relevant STEs.

Language: Английский

Citations

17