The erosion of the beach at Mangamaripeta and near the Kursura Submarine Museum has been happening for decades, however, it has increased since 2007. The waves are higher than usual and their height goes up during low pressure or cyclones and during onset of the South West Monsoon.
“The height of the waves during the SW Monsoon (June to September) ranges between 1.5 m and 2.5 m as against the normal height of 1.25 m. It increases during full moon, new moon, low pressure and cyclones. The waves were around 3.2 m high near Mangamaripeta in the past few days. This is a common phenomenon on the East Coast,” says Head of the Department of Meteorology and Oceanography of Andhra University K.V.S.R. Prasad.
“During the North East Monsoon (December to February) waves deposit sand. However, sometimes due to man-made obstructions, the sediment deposition is affected. The decrease in sediment budget (source) aggravates the problem,” he says.
“There is greater erosion of the beach to the north side of ports like R.K. Beach (north of Visakhapatnam Port), Yarada (north of Gangavaram Port) and Uppada (north of Kakinada Port). There is no sediment deposition from the south side due to development of ports and harbours down south,” says Prof. Prasad, who has been studying the coastal areas for the last three decades.
“Due to the geomorphology of the coastline, the waves break in the south east direction and they will transport sediments towards north east side. The construction of ports, harbours and other structures hamper movement of the sediment,” says N.S.N. Raju, a retired Senior Technical Officer of the National Institute of Oceanography and adds that waves attack the coast as there is no porous sediment to reduce their intensity.
“Planting of trees like casuarinas and palm on the coast and prevention of removal of sand from the beaches could minimise beach erosion,” he feels.