Cochin Port is a major port in the Arabian Sea – Indian Ocean Sea – route and is one of the largest ports in India. The commercial port of Cochin in South-East India is situated in a natural bay connected to Kerala’s backwaters. It has the largest siltation rate among Indian ports: more than 20 million m³ per year. Siltation is pollution of water by fine particulate terrestrial clastic material. Siltation occurs mostly during the Monsoon (June-September) when both river discharges and ocean dynamics are high.
The need for continuous maintenance dredging has serious budgetary impacts for the Cochin Port Trust (COPT). Therefore Cochin Port Trust assigned Antea Group, IIC technologies and Stema Systems to collaborate on a study for the analysis of the siltation processes and to assess the feasibility to implement the nautical depth concept. The latter signifies to investigate the nature of the fluid mud seabed and determine to what extent vessels can sail through and manoeuvre in it.
Antea Group experts identified four main parts of the study:
- collect field data to feed the simulation models;
- conduct hydrodynamic and empirical numerical model studies to research the siltation causes and remedies;
- set up and validate a nautical simulation model;
- establish and apply an operational measurement practice to implement the nautical depth and derive dredging volumes.
For the first part Antea Group sediment professionals took various measurements, such as waves, currents, tide, wind, salinity, bathymetry, sea bed composition, suspended sediment concentration and mud rheological properties. This data is used to feed a numerical 2D/3D model and help to simulate various hydrodynamic, morphodynamic and siltation processes. Understanding those processes will allow our experts to research causes of siltation and suggest remedies. In order to investigate the nautical implications of a new nautical depth criterion in the Port of Cochin, simulations are performed. For this part a special tool was used. A ship manoeuvring simulator especially equipped for manoeuvring in mud conditions in shallow ports (Flanders Hydraulics Research). After assessing the feasibility for a nautical depth for the Port of Cochin, monitoring and maintenance methods are investigated as well as the implications for dredging.
Duration: approximately 18 months.