Beach nourishment at Veli and Poonthura, a challenging task

Thiruvananthapuram: The sandy beaches in the district are being eaten away by strong waves at an alarming pace, resulting in loss of homes and livelihood. Minister for Transport Antony Raju – who represents Thiruvananthapuram assembly constituency – has pitched up the idea of beach nourishment along Poonthura and Veli. Experts associated with coastal restoration and wave dynamics welcomed the move and added that it has to be done with utmost scientific knowledge and based on long-term sustainability quotient.

Beach nourishment hinges mainly on maintaining the natural slope equilibrium, they pointed out. “There is no harm in artificial sand deposits to prevent coastal erosion. The success of such a process depends on long-term sediment availability and we need measures to sustain sand. The depth of sea along Trivandrum coast has increased considerably. There should be a proper study on how and where the deposit shall be done. The quantification of sand deposit at the mouth of the harbour has to be accurate. Beach nourishment will take time to yield results,” said coastal scientist KV Thomas. Natural, man-made factors have contributed equally to depletion of sediment deposit on beaches along the district coast, other scientists added. Cumulative erosion has been detrimental to the beaches.

“We used to have a regular weather pattern like monsoon from June to Sept and then we would have a fair patch which will begin from Oct till Apr. This period used to witness a natural beach building process. We could assume that even if beaches got washed away during rain, part of it or even more would come back in the following months. This process has not been happening in Trivandrum in the way we expect in the past four years. Periodic cyclonic activity, storm conditions, extreme rain and some man-made reasons may have resulted in this. If beach nourishment has to yield a solution, it has to be done for a prolonged period,” said another senior coastal scientist.

Beach nourishment is being successfully done at Visakhapatnam as an annual project for Vizag port. There has been a notable increase in the beachfront area following this process. “If Vizag model is to be replicated here, we have to lay focus even on the nature of material being deposited. There should be 5 years of nourishment. The material should be almost similar to the original material and share the same characteristics. We need to revive the same process and equilibrium slope has to be maintained,” said anexpert.

It is yet to be ascertained whether the proposed beach nourishment will coincide with the shore protection work set to begin at Poonthura. Raju said that Dr MS Swaminathan report shall be implemented to maintain ecological balance in coastal areas. “Deposit of sand is the important step in preventing coastal erosion. The firm engaged in construction of Vizhinjam harbour is not willing to deposit sand along the coastal area and emergency directions shall be given to it,” he said.