ABSTRACT
In this chapter, three different cases for tidal dynamics in a coastal aquifer will be discussed. First, the steepness expansion is proposed. The conventional approaches for tidal dynamics in coastal aquifers have been based on the shallow water expansion for both vertical and sloping beaches. The applicable range of the shallow water expansion will be the limit of two parameters, shallow water parameter and amplitude parameter. In this chapter, a new perturbation parameter, steepness parameter, is proposed to extend the applicable range of the solution. Second, the solution for tidal fluctuations in a leaky confined aquifer is outlined. In real coastal aquifer, both phreatic and confined aquifer responses could be co-existed. Most studies treat phreatic and confined aquifers independently, i.e., without leakage effects. In this chapter, we will outline the analytical solution for the tidal fluctuations in a leaky confined aquifer. Finally, most existing studies for tidal dynamics in coastal aquifer focus on single tidal period. However, in reality, tides are more complicated and often bi-chromatic, containing oscillations of at least two different frequencies. In this chapter, an analytical solution for spring-neap tide-induced watertable fluctuations is presented.
