Analytical Solution of Tidal Loading Effect in a Submarine Leaky Confined Aquifer System

Zongzhong Song,Chunmiao Zheng,Qian Ma,Hailong Li,Jiu Jimmy Jiao,Shaohong Li

doi:10.1155/2019/8017164

Abstract

Although there are many existing analytical studies of tidal groundwater level fluctuations in coastal aquifer systems, few of them focus on an offshore submarine aquifer. Here, we consider tidal groundwater head fluctuations in a submarine leaky confined aquifer overlain by a semipermeable seabed. Both the seabed and the confined aquifer are assumed to extend horizontally infinitely. A one-dimensional mathematical model is established to describe the problem, and the analytical solution is derived. The impacts of the tidal loading efficiency, hydraulic conductivity and elastic storage of the semipermeable layer and aquifer on the groundwater head fluctuations in the aquifer system are analyzed and discussed. Solution analyses indicated that tidal loading effects tend to enhance the amplitude of the tidal groundwater fluctuation in the confined aquifer system and to reduce the phase shift between the groundwater head and the sea tide fluctuations.

Highlights

The study of tidal groundwater level fluctuations in coastal aquifer systems is beneficial to solving various coast environmental problems
Jiao and Tang [12] discussed the tide-induced groundwater head fluctuation in an onshore multilayered coastal aquifer system neglecting the elastic storage of the semipermeable layer
All the effects related to the semipermeable layer such as the elastic storage, the leakage, and the tidal loading efficiency were taken into account

Summary

Introduction

The study of tidal groundwater level fluctuations in coastal aquifer systems is beneficial to solving various coast environmental problems. Various analytical solutions related to tidal head fluctuations have been derived for coastal confined aquifers. Jiao and Tang [12] discussed the tide-induced groundwater head fluctuation in an onshore multilayered coastal aquifer system neglecting the elastic storage of the semipermeable layer. Based on Jiao and Tang’s study [12], Li and Jiao [13] took into account the elastic storage of the semipermeable layer, and they [14] considered a leaky aquifer with the roof extending under the sea. All the effects related to the semipermeable layer such as the elastic storage, the leakage, and the tidal loading efficiency were taken into account. All effects related to the submarine leaky confined aquifer system such as the elastic storage, the hydraulic conductivity, and the tidal loading efficiency were taken into account. The influences of the tidal loading efficiency, the elastic storage, and the hydraulic conductivity on the tidal groundwater head fluctuations in the confined aquifer and in the seabed were analyzed and discussed

Mathematical Model and Analytical Solution

Case 1

Discussion of the Solution

Case 2

Groundwater Head at Different Depths of the Confined

Conclusion