Propagation of tides in the Mandovi and Zuari estuaries

The Mandovi and the Zuari are two shallow estuaries that are located in Goa and join the Arabian Sea. The main channel of each is about 50 km long, has its cross-sectional area decreasing rapidly in the upstream direction, and receives large amounts of riverine freshwater during the southwest Monsoon and little during the rest of the year. Tides in the channels exhibit the following characteristics: (a) The speed of propagation is about 6.5 m s−1; (b) tidal amplitude remains unchanged over a distance of about 40 km from the mouth; (c) mean water level near the head increases with increase in runoff; (d) tidal amplitude decays rapidly over ≈ 10 km near the head, the decay is more rapid during periods of higher runoff.