Why were historical period ports of Goa located away from the coast? The decline of Gopakapatana

摘要

Most of the ports of the historical period of the east and west coasts of India were located away from the seafront. But in later period, new ports were established mostly along the coastal regions. The reasons attributed to abandoning inland ports are: (a) bigger ships, which had to carry more cargo, (b) larger vessels could withstand the flow of current, (c) advancement in shipbuilding and navigation techniques, and (d) sediment deposition leading to navigational hazards. In the case of Goa, Chandrapura (Chandor) was the oldest inland port. During the later epoch, port activity shifted downstream to Gopakapatana, on the northern bank of the River Zuari. During the 15th century AD, Old Goa, on the bank of the Mandovi River, served as an important trade centre. Most modern port in Goa was built at Mormugao in 1885 in the Zuari estuary. This paper delineates the most likely cause for the decline of Gopakapatana, in particular, as a trade centre, from a geo historical and oceanographic perspective. A detailed look into the evolution of the morphology of this river bank reveals rapid accretion that led to the formation of a shallow feature. A comparative study of maps of 1923, 1962-64, 2003 and modern images of 2010 confirm that the area is now occupied by a mud flat that extended by 68% during the last 40 years.