The use of subsurface physical barriers to control seawater intrusion in heterogeneous coastal aquifers

: Experimental and numerical study

Abstract

The purpose of this thesis was to use laboratory and numerical modelling tools to provide an insight on the impact of subsurface physical barriers on seawater intrusion and flow dynamics in commonly found heterogeneous formations and to propose the mixed physical barrier (MPB) as a new countermeasure for seawater intrusion control purposes. In overall, this thesis is subdivided into eight chapters. The first chapter provides some relevant literature pertaining to this research, lists the objectives and presents a brief preview of each chapter. The second chapter provides a description of the general methodology adopted in this research as well as the details of the all experimental settings investigated herein. The third chapter presents a analysis of the response of seawater intrusion and retreat to incremental water level variations. The fourth chapter provides an analysis of the saltwater upconing mechanism in response to groundwater abstraction. The fifth chapter addresses the effect of cutoff walls on seawater intrusion in multi-layered heterogeneous aquifers. The sixth chapter provides and insight on the impact of layered heterogeneity on the ability of subsurface dams to control seawater intrusion. The seventh chapter demonstrates the viability of the MPB and compares its effectiveness to traditionally-used barriers. The eighth and final chapter summarizes the main findings and offers some recommendations for future works.

Date of Award	Dec 2017
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Queen's University Belfast
Supervisor	Ashraf Ahmed (Supervisor), Salissou Moutari (Supervisor) & Gerard Hamill (Supervisor)