Original paper

Beach dynamics of Colachel open coast, Kanyakumari District (SW India)

Hentry, C.; Chandrasekar, N.; Saravanan, S.

Abstract

In order to study the beach dynamics of Colachel on the Kanyakumari coast, field investigations were carried out on the beach profiles, breaking wave parameters and longshore currents for a period of 25 months from December 2006 to December 2008. Monthly measurements were made on littoral environmental observations (LEO) and beach level variations. Long shore sediment transport rates were estimated based on the observed data. The estimated annual gross long shore sediment transport rate was higher due to recent manmade structures and the net transport was towards west. The beach level was lowest in July and high in April and the range was 75 m. The total volume of sand transported is 1,810 m3 only. The range of wave heights was between 0.5 to 2.5 m during 2007 and 0.5 to 2.2 m during 2008, whereas wave period was between 8 sec to 15.5 sec and 9.2 sec to 12.8 sec for 2007 and 2008 respectively. The study indicated that the beach is essentially stable but showing only seasonal fluctuations. Colachel, which is being subjected to erosion phase during Southwest monsoon season regained the profiles by January or February. Longshore currents were stronger in June, July and August and steady during rest of the year. The net westerly transport was approximately 0.9 × 106 m3 during 2007 and 0.3 × 106 m3 during 2008.

Keywords

longshore currentsediment transportbeach profilebreaking waves