Estimation of groundwater flow along complex coastal aquifers in presence of tidal waves

Abstract

ABSTRACT Coastal aquifers are of interest for many years in understanding the transient interaction of tides and groundwater. With existing studies, water table fluctuations in the two zonal aquifers of various configurations separated by horizontal or sloping bases have been addressed; however, flow properties in respective aquifers are not addressed. The present study is an application of the previous study and it addresses flow properties such as flow rate at both ends of the complex coastal aquifer, and volumetric exchanges of groundwater at the proximity surface and at the boundary point. The combined effect of the bed slope and tidal waves on groundwater flow properties is addressed by obtaining the analytical expressions. Furthermore, numerical simulation using a finite difference method (FDM) is carried out for the flow rate and analytical solution is compared with it and found to be satisfactory. The hydrographs representing the flow rate and amount of groundwater exchanged are studied with different bed slopes and for various time lags. The flow analysis is carried out in a heterogeneous aquifer by changing various hydrological parameters. The study focused on dependency of groundwater hydraulic properties for the sloping zone on the horizontal zone. Based on the results, the groundwater flow in the complex aquifer systems is discussed.