In coastal regions of Australia and throughout the world, the water table height fluctuates with the actions of tides and of wave run up and run down. The fluctuation of the water table height affects the beach ecosystems in many ways including oxygenation, sediment transportation, and a number of biological processes. In the past there have been a number of attempts made to model these watertable table fluctuations, along with the total moisture contents. This thesis proposes to continue and expand on previous work in this area.
This was done through extensive experimental work using a sand column where the piezometric driving head was applied at the base of the column as a simple harmonic function. The driving head and a sand water level height were measured using accurate pressure transducers. The watertable height could then be calculated from the sand water level measurements. The amplitude, time periods and average head levels of the driving head were all varied.
From the experimental data, the fluctuation of the water table as it followed the driving head was attempted to be modelled as simple harmonic sinusoidal curves.
The data was further analysed to determine whether this was an accurate assumption, or whether non linear (2nd order) effects should be included.
The data was also analysed to determine the porosity of the sand, and the hydraulic conductivity. To take into account the effects of hysterises and other capillary effects in the region just above the watertable, the porosity was determined as a complex dynamic effective porosity.
This thesis attempts to continue the work in these areas, and to determine whether the modelling processes and assumptions made are valid.