Tidal Analysis of the Coomera River Estuary

Abstract

This paper describes development of a numerical tidal model and a data collection program for the Coomera River estuary on the Gold Coast. The primary objective of this exercise is to provide a detailed picture of the tidal characteristics within the study area; to investigate the degree and importance of tidal asymmetry at the Coomera River; to calculate tidal prism; and also to enable the simulation of the water circulation within the study area. A comprehensive data set is collected as part of this study to understand local dynamics and to calibrate and validate the model. The collected data include current, water level and meteorological forces in the study area. Calibration and validation have been achieved through: ð€‚ƒ Comparison of computed tidal harmonics against those derived from harmonic analyses of the measured water level variations, and ð€‚ƒ Comparison between the measured discharges across four cross sections at critical locations of the study area with the discharges obtained through modelling. As part of this study harmonic analysis of the collected data were conducted to identify the major tidal constituents of the tidal signal within the study area. Calculations show that tide becomes mixed, mainly semidiurnal in the estuary.