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

An analytical solution is derived to investigate the influence of leakage o n tidal response in a coastal leaky confined aquifer system. The analytical solution developed here is more general than the traditional solution obta ined by Ferris [1951], which can be regarded as a special case of the solut ion presented in this paper. This solution is based on a conceptual model u nder the assumption that the groundwater level in the confined aquifer fluc tuates in response to sea tide while that of the overlying unconfined aquif er remains constant. This conceptual model is supported by numerous field s tudies by previous researchers which have demonstrated that the tidal respo nse in an unconfined aquifer may be negligible compared to that in a confin ed aquifer. The leakage has a significant impact on the tidal behavior of t he confined aquifer. Hypothetical studies indicate that both tidal amplitud e of groundwater head in the aquifer and the distance over which the aquife r can be disturbed by the sea tide will be considerably reduced because of the existence of leakage. This analytical solution is used to investigate t he tidal and piezometer data at the Chek Lap Kok airport, Hong Kong Special Administrative Region, People's Republic of China.