Beach changes during normal and cyclonic periods along Visakhapatnam Coast

Abstract

Wave data in the breaker zone have been collected during September 1982 to September 1983 through daily observations. The most predominant waves that approach the coast are from SSE during the SW monsoon (May to September) and from E during the NE monsoon (November to February). Predominant wave periods are around 10 sec, and the breaker heights very widely from station to station depending on the topography of the coast. Wave refraction studies reveal in general a pattern of wave divergence all along the coast. Quantitative aspects of sediment transport across different cross-section of the beach are studied for different months and discussed in relation to the morphological and meteorological conditions of the region. The beaches are eroded during February to October and are again filled partially between October February. Scattered rocky out-crops at different points across the littoral zone affect the sediment transport significantly, causing reversal in beach cycles on the southern side of such rocky barriers. Beach changes during cyclone periods are presented for a few case studies.