An analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer

Abstract

Abstract. An analytical solution is derived to investigate the influence of leakage on tidal response in a coastal leaky confined aquifer system. The analytical solution developed here is more general than the traditional solution obtained by Ferris [1951], which can be regarded as a special case of the solution presented in this paper. This solution is based on a conceptual model under the assumption that the groundwater level in the confined aquifer fluctuates in response to sea tide while that of the overlying unconfined aquifer remains constant. This conceptual model is supported by numerous field studies by previous researchers which have demonstrated that the tidal response in an unconfined aquifer may be negligible compared to that in a confined aquifer. The leakage has a significant impact on the tidal behavior of the confined aquifer. Hypothetical studies indicate that both tidal amplitude of groundwater head in the aquifer and the distance over which the aquifer can be disturbed by the sea tide will be considerably reduced because of the existence of leakage. This analytical solution is used to investigate the tidal and piezometer data at the Chek Lap Kok airport, Hong Kong Special Administrative Region, People's Republic of China. IntroductionIn most coastal areas, groundwater and seawater are in con- While the tidal fluctuation in an unconfined aquifer may be negligible compared to that in a confined aquifer, the unconfined aquifer may influence the tidal fluctuation in the underlying confined aquifer via leakage. To the authors' knowledge, there has not been any research to address this issue. In this paper an attempt will be made to develop an analytical solution to investigate the influence of leakage on tidal response in a coastal leaky confined aquifer system. This solution will then be used to discuss the impact of leakage on the tidal behavior of the confined aquifer. The tidal and piezometer data at the Chek Lap Kok (CLK) airport, Hong Kong Special Administrative Region, People's Republic of China are used as a case study.

Preliminary numerical study on groundwater system at the Hong Kong International Airport

“…The mud was dredged prior to reclamation and replaced by fill materials, which consist of marine sands and rock boulders. The fill materials become a very good unconfined aquifer (Jiao and Tang, 1999).…”

Vulnerability of Eco-Hydrological Environment in the Yellow River Delta Wetland

“…Since the 1950s, a large number of analytical studies have been conducted on how groundwater responds to tidal fluctuation (Jacob, 1950;Jiao and Tang, 1999;Li et al, 2002Li et al, , 2007Nielsen et al, 1997;Sun, 1997;Townley, 1995;Trefry and Bekele, 2004). Most of these studies assumed that the aquifer is homogeneous.…”

Comment on “An analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer” by Jiu Jimmy Jiao and Zhonghua Tang

“…Jiao and Tang [1999] presented an analytical solution of groundwater fluctuation in a coastal aquifer system consisting of a confined aquifer, a semipervious layer, and an unconfined aquifer. There are two major assumptions used by Jiao and Tang [1999] in deriving the solution. First, the groundwater fluctuation in the unconfined aquifer is assumed to be negligible, and hence the water head remains constant and equal to that imposed at the inland boundary.…”