Tidal Circulation and Salinity Distribution in the Mandovi and Zuari Estuaries: Case Study
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 135, Issue 6
Abstract
The Mandovi and Zuari are two tropical estuaries along the west coast of India, characterized by mixed tides with semidiurnal dominance and heavy fresh water influx during the southwest monsoon (June to September). Previous observations of tides in these estuaries show that the tidal effects in the upstream regions are subject to decay due to freshwater influx during the southwest monsoon. The longitudinal distribution of salinity in these estuaries undergoes large variations between the southwest monsoon and the dry season (February to May). The main objectives of the present study were to simulate the tidal circulation, the longitudinal distribution of salinity, and the freshwater influence on tides and the salinity distribution. Another objective was to study the intraseasonal variations of salinity during the breaks in the southwest monsoon. A hybrid network numerical model was used for the present study to simulate the tidal circulation and the salinity distribution in these estuaries. The model reproduced observed tides accurately during the dry and wet seasons. The model could reproduce the longitudinal distribution of salinity well during the dry season and the simulation of salinity distribution was reasonably well during the wet season. The simulated tidally averaged salinities over the tidal period for varying river discharges show that even a small freshwater influx can affect the longitudinal distribution of salinity to a great extent in this type of estuaries.
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Acknowledgments
The authors thank the Central Water Commission, New Delhi for providing the discharge data. The first author thanks University Grants Commission, Government of India, for providing a research fellowship to carry out the work. Acknowledgment is extended to the Captain and the crew of research vessel, Sagarsukti, for their help during the field surveys and to our colleagues Dr. M. Aparna, Dr. Mohammed Al Saafani and Mr. K. Suprit for their suggestions and support throughout this work. The authors thank Dr. S. R. Shetye for his valuable suggestions to improve the manuscript. The model simulations of this work were done on SGI ALTIX 350 Cluster installed in the Hydrodynamic Laboratory, NIO. This is NIO contribution number 4562.
References
Cherian, T., Rao, L. V. G., and Varma, K. K. (1975). “Variation in physical characteristics of the waters of Zuari estuary.” Indian J. Marine Sciences, 4, 5–10.
De Sousa, S. N. (1977). “Monitoring of some environmental parameter at the mouth of Zuari estuary.” Indian J. Marine Sciences, 6, 114–117.
De Sousa, S. N. (1999). “Consultancy services for disposal of treated sewage effluents in the estuary of River Mandovi at Campal, Panaji.” Rep. No. TR—8633, NIO/SP—16/99 1999, Public Work Department (PWD), Government of Goa, National Institute of Oceanography, India.
De Sousa, S. N. (2000). “Consultancy services for disposal of treated sewage effluents in the estuary of River Mandovi at Campal, Panaji.” Rep. No. TR—8658, NIO/SP—21/2000 2000, Public Work Department (PWD), Government of Goa, National Institute of Oceanography, India.
De Sousa, S. N., Sengupta, R., Sanzgiri, S., and Rajagopal, M. D. (1981). “Studies on nutrients of Mandovi and Zuari River systems.” Indian J. Marine Sciences, 10, 314–321.
Elliot, B. A., and Reid, R. O. (1976). “Salinity induced horizontal estuarine circulation.” J. Wtrwy., Harb. and Coast. Engrg. Div., 102(WW4), 425–442.
Harleman, D. R. F., and Lee, C. H. (1969). The computation of tides and currents in estuaries and canals, Massachusetts Institute of Technology, Cambridge, Mass.
Manoj, N. T., Unnikrishnan, A. S., and Sundar, D. (2009). “Tidal asymmetry in the Mandovi and Zuari estuaries, the west coast of India.” J. Coastal Res. ).
POL/PSMSL. (2000) Tidal analysis software kit 2000 (TASK-2000), Proudman Oceanographic Laboratory, Merseyside, U.K.
Qasim, S. Z., and Sen Gupta, R. (1981). “Environmental characteristics of the Mandovi-Zuari estuarine systems in Goa.” Estuarine Coastal Shelf Sci., 13, 557–578.
Shetye, S. R., et al. (1995). “Propagation of tides in the Mandovi and Zuari Estuarine Network.” Proc., Indiana Acad. Sci. (Earth and Planetary Sciences), 104, 667–682.
Shetye, S. R., and Murty, C. S. (1987). “Seasonal variation of the salinity in Zuari Estuary, Goa, India.” Proc., Indiana Acad. Sci. (Earth and Planetary Sciences), 96, 249–257.
Sinha, P. C., Rao, Y. R., Dube, S. K., Rao, A. K., and Chattergee, A. K. (1996). “Modeling of circulation and salinity in Hooghly estuary.” Mar. Geodesy, 19, 197–213.
Sundar, D., and Shetye, S. R. (2005). “Tides in the Mandovi and Zuari estuaries, Goa, West Coast of India.” J. Earth System Sciences, 144, 493–503.
Thatcher, M. L., and Harleman, D. R. F. (1972). Prediction of unsteady salinity intrusion in estuaries mathematical model and user’s manual, Massachusetts Institute of Technology, Cambridge, Mass.
Unnikrishnan, A. S., Shetye, S. R., and Gouveia, A. D. (1997). “Tidal propagation in Mandovi and Zuari estuarine network, west coast of India: Impact of fresh water influx.” Estuarine Coastal Shelf Sci., 45, 737–744.
Unnikrishnan, A. S., Shetye, S. R., and Michael, G. S. (1999). “Tidal propagation in the Gulf of Khambhat, Bombay high and surrounding areas.” Proc. Indiana Acad. Sci. (Earth and Planetary Sciences), 108, 155–177.
Varma, K. K., Rao, L. V. G., and Cherian, T. (1975). “Temporal and spatial variations in hydrographic conditions of Mandovi estuary.” Indian J. Marine Sciences, 4, 11–17.
Vecchi, G. A., and Harrison, D. E. (2002). “Monsoon breaks and subseasonal sea surface temperature variability in the Bay of Bengal.” J. Clim., 15(12), 1485–1493.
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Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 135 • Issue 6 • November 2009
Pages: 278 - 287
Copyright
© 2009 ASCE.
History
Received: Jan 15, 2008
Accepted: Jun 24, 2009
Published online: Oct 15, 2009
Published in print: Nov 2009
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