STUDY ON COASTLINE CHANGES AND SEDIMENT TRANSPORT ALONG ENNORE COAST, SOUTH INDIA - A NUMERICAL MODELING APPROACH

摘要

Coastal engineering practice is undergoing, and will continue to undergo, rapid changes. The coastline changes are natural phenomena and are complicated and difficult to understand. The prediction of the behaviour of coastline becomes further complicated due to the interference of coastal structures. The Danish Hydraulic Institute has developed a system of computer modules based on this approach namely MIKE 21 and LITPACK. This has been applied to study the impact of breakwaters of Ennore Port on the Ennore coast located on the southeast coast of India. This study has been taken up in order to identify the immediate effect of the port since the port has been commissioned only in 2001. A typical coastline of 13.5 km length has been selected of which 5 km is on the southern side of the south breakwater and 6 km on the northern side of the north breakwater. In between, the port length is of 2.5 km. The simulation has been carried out for a period of 30 years in order to know the future trend of the coastline. From the results, it is evidenced that severe accretion is taking place in the southern side of the Ennore port. In the northern side of north breakwater, it is seen that erosion will be taking place for a width of upto 100 m and 200 m during the 1st and 2nd years respectively. Littoral drift in the study region shows that more or less equal amount of sediment transport is taking place at all the three profiles. The net annual transport rate is towards the northern direction. Results are in good agreement with the actual field conditions. It is concluded that enormous accretion is taking place in the southern side of the port and erosion has started in the northern side. In order to prevent the adverse impacts the authorities should take immediate measures.