MOHANTY, P.K.; PATRA, S.K.; BRAMHA, S.; SETH, B.; PRADHAN, U.; BEHERA, B.; MISHRA, P., and PANDA, U.S., 2012. Impact of groins on beach morphology: a case study near Gopalpur Port, east coast of India.
Gopalpur Port is being developed as an all-weather open seaport from a fair-weather port which has existed since 1987. Two groins, a 530-m south groin and a 370-m north groin, were constructed during the periods from August 2007 to November 2009 and October 2007 to September 2008, respectively, on the north and south of the 500-m jetty which existed earlier. Port authorities are planning to construct a southern breakwater and a series of seven northern groins. Therefore, it is essential to assess the impacts of coastal structures on beach morphology and shoreline change in the present context and to predict future trends. To achieve this, a long-term observational programme has been conducted since May 2008. Observations include beach profile, shoreline change (berm position), littoral environment observations, and sedimentological characteristics at monthly intervals north and south of the port, covering a total distance of about 5 km. From the analysis of results, erosion is observed north of the northern groin, particularly during the monsoon season. From October to January, deposition is observed mostly in the foreshore which replenishes the erosive environment observed during monsoon. On the other hand, a constant depositional trend is noticed south of the southern groin for 1.5 km. To assess the impacts of the present groins, beach profile and sediment characteristics were compared with observations made from February 2002 to February 2003. The comparison distinctly shows the impact of groins on erosion and deposition on the north and south beaches of the port. Volume, beach width, and beach area estimates indicate that the rate of deposition on the south beach is much faster than the rate of erosion on the north.