Water Circulation in 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 project was 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 the tidal prism; and also to enable the simulation of water circulation within the study area. A comprehensive data set was collected as part of this study to understand the 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 were achieved through: comparison of computed tidal harmonics against those derived from harmonic analyses of the measured water level variations; and comparison between the measured discharges across four cross-sections at critical locations within the study area with the discharges predicted through modelling. As part of this study, harmonic analyses 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, and is mainly semi-diurnal in the estuary.

Key Words:

• Tide
• tidal prism
• hydrodynamic model
• harmonic analysis

Additional information

Notes on contributors

H Mirfenderesk

Dr Hamid Mirfenderesk is the Team Leader of the Gold Coast City Council Waterways and Flood Management section. Hamid also works as a casual lecturer at the Queensland University of Technology and holds an Adjunct Associated Professor at the Griffith University. He has more than 20 years engineering and academic work experience in water engineering. Hamid holds PhD in Coastal Engineering, Master of Science in Civil Engineering and Graduate Diploma in Information Technology from the University of New South Wales. He also has a Bachelor of Engineering Science in Civil Engineering from the Tehran University.

R Tomlinson

Prof Rodger Tomlinson is Foundation Director of the Griffith Centre for Coastal Management at the Gold Coast Campus of Griffith University. The centre was established in 1999 in partnership with the Gold Coast City Council, and currently has a broad range of national and international research and community education activities of relevance to sustainable coastal management. Rodger served as the Head of School of Environmental Engineering at Griffith University from 1994 to 2000, and was the Theme Leader for Planning Management and Restoration Options in the Coastal CRC from 1999 to 2006. In recent years, Rodger has held the position of Director of the Griffith Climate Response Program, and is currently the Coastal Settlements Node Convenor for the Australian Climate Change Adaptation Research Network for Settlements and Infrastructure. He also represents Griffith University on the Management Committee for the National Climate Change Adaptation Research Facility. His current research interests are in the areas of climate variability, climate change, and the implications for open coastline and coastal waterway dynamics and management.

L Hughes

Lawrence Hughes is a Senior Technical Officer at the Griffith Centre for Coastal Management. He is actively engaged in numerous estuarine and coastal inshore studies, during which time he has developed a number of innovative systems and co-authored papers that assist with the understanding of the complex coastal and inshore oceanic region. After graduating from Bangor University in 1983 with an honours degree embracing sedimentology, oceanography, geophysics and marine biology, Lawrence spent two years gravity surveying along the East African Rift Valley, from Oman to Mozambique, before establishing his own consultancy GEOS, a geophysical exploration company developing autonomous computer-based data collection system for use in the new field of environmental monitoring. Lawrence migrated to Australia in 1991, and specialised in acid sulphates and environmental investigations along the eastern seaboard of Australia for four years from Burketown to Macleay. The drought forced a sea-change move from investigating the viability of Red Claw crayfish farming on the Queensland Granite Belt to a PhD candidate investigating the role of coastally-trapped internal waves on sediment transport along the east coast of Australia at Griffith University.