Longshore currents and sediment transport along Kannirajapuram Coast, Tamilnadu, India

The objective of the study was to estimate longshore current and sediment t ransport from measured wave data and from the observations on the littoral environment. A directional wave rider buoy was deployed at 12m water depth, 11 km off Kannirajapuram. Wave data at 3 hourly intervals from March 1997 to February 1998 were recorded. The first wave direction corresponding to t he peak of the spectrum and second wave direction corresponding to the seco ndary peak were estimated since wave spectrum at this location was mainly d ouble peak spectrum. Daily observations on surf zone width and longshore cu rrents were carried out at Kannirajapuram beach during March 1997 to Februa ry 1998. The longshore currents and sediment transport were estimated consi dering first and second breaker angles and resultant was estimated consider ing the ratio of the first and second spectral energy peaks. Comparison of measured and computed longshore current shows that currents can be reasonab ly well estimated based on Galvin's equation and sediment transport based o n Walton's equation.