Study finds no correlation between coast erosion and Vizhinjam port project

A study headed by a US-based researcher Dr. Clement Lopez, a former researcher at the Department of Future Studies, University of Kerala, says the construction of the Vizhinjam International seaport is not the causative factor for the accelerated erosion along the coastline of Thiruvananthapuram. The study which analysed various factors including the pattern of shoreline changes along the coastline from 1985 to 2022 and around 15 pre-requisites to dissect the real causative factors of beach erosion in terms of port, groins, climate/cyclones, harbor, etc., found no correlation between the port project and the erosion along certain stretches of the coastline.

The study which assumed significance in the light of the agitation by fisherfolk alleging that the project had resulted in intense erosion of beaches, affecting their livelihood., revealed that in beaches adjacent to the north of the port like Poonthura, Beemappally, Cheriyathura, the erosion was on a diminishing or decelerating scale during the period from 2015-2022 compared to the shoreline data of 2003-2015. Further, there was considerable beach accretion in Beemappally and Cheriyathura in recent times as a result of groins built in the area to check erosion.

On the flip side, in Valiayathura, Thope, and Shanghumugham beaches, the erosion continued during the 2015-2022 period like in the pattern of the pre-port construction phase. If the port was the causative factor, the port-induced erosion should be severe in beaches close to the port like Poonthura, then Beemappally and Cheriathura after 2016 (Port construction began), and then on a diminishing scale in the coming beaches like Valiathura, Thope, and Shangumugham beaches. But here the erosion was insignificant on the first three beaches close to the port and on a steady increase on the next three beaches like in the pre-port phase, the study said.

In short, there is no correlation between erosion and port. But seven groins built at Poonthura in 2011 caused erosion in Beemapally and Chariathura, and then five groins in Cheriathura in 2017 and 7 groins in Beemapally in 2018 caused severe erosion in Valiathura, Thope, and Shangumugham. Port-induced erosion cannot fly to Valiathura, Thope, and Shangumugham beaches, without causing erosion in the beaches before such as Poonthura and Beemapally, which are near to the port, said Mr. Lopez, Director, DRC SOFT, USA – a startup to promote digital skills and soft skills among the communities.

The study also found that the ‘bay effect’ of the Kovalam cliff – the Vizhinjam harbour and port are within the bay – is the real reason behind the erosion. For instance, a bus stopping at the bus bay doesn’t affect the traffic on the road. The longest projection of the Kovalam cliff is 1,466 meters, whereas the length of the port’s breakwater towards the sea is 1,350 m. Traditionally, the Kovalam Cliff and the Azhimala which stretches about 11.7 km into the sea, is a groin-like structure, a natural projection into the sea, causing accretion on its southern side and erosion on the north side. Exceptional erosions during certain years were caused by 20 cyclones that formed over the Bay of Bengal and the Arabian Sea in the three years period 2018, 2019, and 2020, the study said.