A Simulation Model of Seepage Face Dynamics on Macro-tidal Beaches

A common characteristic of macro-tidal beaches is a distinct break in slope in the intertidal profile. It is proposed that this feature results from the intersection of the beach water table with the intertidal beach face. As a primary step to modelling this process, a simulation model (called 'SEEP') is developed to reproduce the dynamics of a water table seepage face across the intertidal profile of macro-tidal beaches. Despite the simplifying assumption that seepage face motion develops as a results of gravity alone (i.e. the pressure distribution within the beach is ignored) the model successfully reproduces seepage face dynamics recorded on North Harbour Beach, central Queensland (spring tide range = 6.5 m). Sensitivity analysis reveals the critical choice of correct sediment and profile slope parameters.