Two projects of the previous plan period , 'Baseline data collection of aquaculture farms' and other 'Oceanographic Measurements along North Madras and Pondicherry coast' were completed and results were analysed. A short term project work on developing a frustum of a cone as a breakwater armour unit was taken up. A 5-day workshop for 'Ports and Harbour Designers' was conducted during February 23-27, 1998.

11.3.1 Oceanographic Measurements along North Madras and Pondicherry Coasts

This project was sanctioned to Ocean Engineering Centre, IIT, Chennai, with the objective of validating and calibrating the numerical model on near shore wave transformation. M/s. RITES, New Delhi, was assigned the responsibility of making the field measurements on bathymetry and current and wave data, over three seasons in a year. Beach profiles at 10 locations, sediment sampling at 14 locations and current measurement at 13 locations were made. Validation and Calibration exercise has been completed . The major conclusions on pattern of sediment deposition, beach profiles, suspended silt concentrations off Chennai coast have been drawn.

11.3.2 Base line data collection of aquaculture farms

This project was sanctioned with the objective of collecting base- line data for aqua farms which could then be used for in-house water quality models. Field measurements have already been completed and draft final report has been reviewed. The results of this monitoring and modelling work were presented at ISOPE-97 conference.

11.3.3 Mathematical and Field Studies in Coastal Processes

This programme is being carried out under two projects :

(i) Modelling of Nearshore Wave Transformation and Sediment Transport

(ii) Studies on sediment transport and deposition at the mouths of Pulicat lake and Cooum river

Modelling of Nearshore Wave Transformation and Sediment Transport


The near shore coastal phenomenon is a complex physical process. NIOT took up the in-house software development for the near shore hydrodynamic processes. An efficient model for near shore hydrodynamics was developed and verified. Preparation of a detailed theoretical manual is nearing completion. A user-friendly pre-and post-processor is also being developed.

The development of a computer programme for sediment transport is under progress. This programme will be finally converted into a user- friendly application software for studying sediment transport for various engineering applications.

Studies on Sediment Transport and Deposition at the Mouths of Pullicat lake and Cooum river

Seasonal closure of coastal inlets of Cooum River and Pulicat Lake has a disturbing effect on developmental and other social activities, pollution and bio-diversity. This closure of coastal inlet is mainly due to deposition of littoral sediments. The objective of this project is to understand the process and arrive at a suitable engineering solution to maintain the mouths open so that there is a continuous tidal exchange allowing biological regeneration and navigation. As a part of this project, available information on earlier studies on Cooum River and Pulicat Lake Mouths are being collected. Usage of satellite data for analysis of stability of coastal inlets is also being examined.

11.3.4 Theoretical and Experimental Studies on Coastal and Ocean Structures

As a result of liberalisation, coastal structures forming part of the essential infrastructure are gaining great attention. During the previous plan period, laboratory model tests were constructed on floating breakwaters in the NSTL, Vizag. A software has been developed for the analysis of floating breakwaters and its testing with reference to laboratory experiments is in progress. This activity is expected to be completed in 1998.

11.3.5 Storm-Surge Modelling

Storm surges are rapid sea level variations induced by cyclonic wind fields. Cyclonic storms cause heavy loss in terms of life and property. The east coast of India is frequently affected by cyclonic storms accompanied by surges. Storms and surges are natural phenomena which can not be prevented. So it is essential to have a prediction model to identify potential coastal regions likely to be flodded due to storm surges so that necessary precaution can be taken well in time. The objective of this project is to develop the capability to estimate the storm surge and their flooding effect (say) along the East coast of India.

A project has been awarded to IIT, Delhi for cyclone prediction in the Bay of Bengal. The IIT,Delhi has been able to develop a limited area fine grid model for Bay of Bengal. The cyclone prediction by the model for past cyclone data agree well with the NCMRWF forecasting. A basic storm surge prediction software using finite element method has been developed by IIT, Chennai and simulation studies for the ocean shelf region between Chennai and Kalingapatnam have been carried out. An inundation model with surge prediction has been developed by IIT, Delhi and the model is being tested with actual topography. NIOT has initiated work on high precision sea level gauges to obtain sea level data for future calibration of surge and inundation software.