Assessing the protective effect of cutoff walls on groundwater pumping against saltwater upconing in coastal aquifers

Antoifi Abdoulhalik, Abdelrahman M Abdelgawad, Ashraf A Ahmed, Salissou Moutari, G Hamill

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)
36 Downloads (Pure)

Abstract

Subsurface physical barriers are amongst the most effective methods to mitigate seawater intrusion in coastal aquifers. The main objective of this study was to examine the impact of cutoff walls on saltwater upconing using laboratory and numerical modelling experiments. Physical experiments were first completed to reproduce the saltwater upconing process in a laboratory-scale coastal aquifer model incorporating an impermeable cutoff wall. Numerical modelling was used for validation purposes and to perform additional simulations to explore the protective effect of cutoff walls against saltwater upconing. The results suggest that the cutoff wall did not substantially delay the saltwater upconing mechanism in the investigated configurations. Laboratory and numerical observations showed the existence of some residual saline water, which remained on the upper part of the aquifer on the seaward side of the wall following the retreat of the saltwater. The protective effect of cutoff walls was noticeably sensitive to the design parameters. Specifically, cutoff walls installed close to the pumping well enabled the implementation of higher pumping rates, therefore a more optimal use of the freshwater, especially for deeper wells. The results highlighted that the penetration depth of the cutoff walls may not necessarily need to exceed the depth of the pumping well to ensure effectiveness, which is of great importance from construction and economic perspectives.
Original languageEnglish
Article number116200
JournalJournal of Environmental Management
Volume323
Early online date14 Sept 2022
DOIs
Publication statusPublished - 01 Dec 2022

Keywords

  • Groundwater abstraction
  • Pumping well salinisation
  • Coastal aquifer management
  • Laboratory experiments
  • Numerical modelling
  • Seawater intrusion
  • Saltwater upconing
  • Subsurface barriers

Fingerprint

Dive into the research topics of 'Assessing the protective effect of cutoff walls on groundwater pumping against saltwater upconing in coastal aquifers'. Together they form a unique fingerprint.

Cite this