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 toundergo, rapid changes. The coastline changes are natural phenomena and arecomplicated and difficult to understand. The prediction of the behaviour ofcoastline becomes further complicated due to the interference of coastal structures.The Danish Hydraulic Institute has developed a system of computer modulesbased on this approach namely MIKE 21 and LITPACK. This has been applied tostudy the impact of breakwaters of Ennore Port on the Ennore coast located on thesoutheast coast of India. This study has been taken up in order to identify theimmediate effect of the port since the port has been commissioned only in 2001. Atypical coastline of 13.5 km length has been selected of which 5 km is on thesouthern side of the south breakwater and 6 km on the northern side of the northbreakwater. In between, the port length is of 2.5 km. The simulation has beencarried out for a period of 30 years in order to know the future trend of thecoastline. From the results, it is evidenced that severe accretion is taking place inthe southern side of the Ennore port. In the northern side of north breakwater, it isseen that erosion will be taking place for a width of upto 100 m and 200 m duringthe 1st and 2nd years respectively. Littoral drift in the study region shows that moreor 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 goodagreement with the actual field conditions. It is concluded that enormous accretion istaking place in the southern side of the port and erosion has started in the northernside. In order to prevent the adverse impacts the authorities should take immediatemeasures.