Even as the government is finalising plans to repair the 150-m seawall and 200-m road devoured by waves along with a major chunk of the Shanghumughom beach, scientists say any coastal protection solution should aim at restoring and preserving the beach.
The suggestions have come at a time when restrictions have been imposed on visitors arriving at the beach that has been retreating, threatening the road leading to the domestic terminal of the airport even before the onset of the monsoon.
Recurrent erosion
It is not the first time that erosion occurs at Shanghumughom, threatening life and property. Crores of rupees have been spent over the years for seawall construction and beach restoration. Further, scientists say if the predicted sea level rise of one metre by 2100 is true, the Thiruvananthapuram international airport would be inundated in the near future.
“Over the years, erosion is taking place at the same spot where the sea wall ends. Emergency steps like laying granite stones and placing sand bags should have been done here to prevent the waves pounding the beach and swallowing the road,” says former scientist of Centre for Earth Science Studies (CESS) K.V. Thomas.
The interventions had led to the present situation as Valiathura had, at one time, a 60-metre-wide beach, Mr. Thomas says, and adds that there is no erosion on the adjoining Pozhiyoor-Adimalathura stretch.
“The beach erosion being witnessed is a classic example of detrimental effects of coastal overdevelopment and human interference with nature,” Joseph Mathew, senior coastal scientist and Director, Sanctuary Beach Private Ltd, Singapore, told The Hindu on Wednesday.
Coastal protection of the Shanghumughom shoreline was rarely required in the past as the beach width was more than 100 m in the 1990s, which has now reduced to 20 m or less even during the calm periods of January and February.
“Coastal protection measures, such as seawalls or groynes, are intended to protect the land, but the structures harden the coast and reduce its ability to adjust naturally,” says Dr. Mathew.
Although the beach-destroying impact of seawalls is well known from the more than 350-km seawalls along the Kerala coast over 50 years, focus on ensuring short-term protection of land and property have diluted all other concerns.
The prescription for saving Shanghumughom from erosion is to “bring back the beach” as the beach offers the best protection, says Dr. Mathew.
Multifunctional coastal protection options as done on the Ullal beach in Karnataka and the Puducherry beach, have to be considered, he says.
Seawall is not a permanent solution, Mr. Thomas says, supporting the views of Dr. Mathew, and arguing for a sediment cell concept that will retain the sediments.
