- Coastal erosion in the southern Indian state of Kerala has destroyed hundreds of homes, forcing families into temporary shelters, many of whom have been stuck there for several years now.
- Experts say a major factor for the erosion is, ironically, the series of seawalls built by authorities along the coastline to prevent the problem.
- The cyclical nature of the erosion has traditionally meant that sediment swept out to sea is later deposited back on land. But the seawalls prevent the latter from happening.
- Other factors have also been cited, including a cyclone that struck the region last year, as well as intensive sand mining along the coast.
KERALA, India — Sixty-five-year-old Maria sits at the doorstep of her demolished house. The only thing that remains is a wall attached to the door. Every morning, she comes “home” and sits there until evening, reminiscing about the times going back to when she and her family started to build their new house.
“My family and I lived in this house just for two years. One night there was an announcement for us to go to a relief camp as the sea was rough. When we returned the next morning the house was ruined by the waves. We were heartbroken,” she said.
Maria lives in the coastal area of Valiyathura in Thiruvananthapuram district, in southern India’s Kerala state. Officially, 110 families have lost their houses in Valiyathura alone because of coastal erosion and rough seas. Another 100 homes have been damaged in the nearby fishing villages of Poonthura, Panathura and Bimapalli, all in the past five years.
About 200 fisher families now live in government schools that function as temporary relief camps. Three or four families live in a single classroom, sleeping on the floor and cooking inside the same room. Many of them go to the shoreline regularly in the mornings to see the remains of their houses. “We are living in this school for the last five years,” Mini, one of the refugees, said tearfully. “My child does not know how to live in a house, he was born here. We had a three-bedroom house there in the first row of houses on the shore.”
Alphine, also from Valiyathura, has had sleepless nights as she fears losing her home to the eroding shoreline. Ten years ago, when her house was built, it was more than 550 meters (1,800 feet) from the shoreline. Now, it is hardly 3 meters (10 feet) away. “Cracks have already appeared in the doors and windows. We have packed our things and are prepared to run away anytime from here,” Alphine said.
In Valiyathura, the most affected coastline of the district, three rows of houses near the sea have been devastated. Another three rows, about 100 houses, are under severe threat. As in the case of Alphine’s house, most of these already have cracks.
Shankhumugam is one of the most popular beaches in the district. The seawall here is completely broken, and the beach has been eroded by the southwest monsoon, which began in June.
According to the shoreline change assessment for Kerala prepared by the National Centre for Sustainable Coastal Management (NCSCM), “a major stretch of Kerala’s coastline (63 percent) is eroding.” The report also says the erosion is highest in Thiruvananthapuram district.
“There are two types of erosion: cyclic and progressive,” D. Ilangovan, senior principal scientist at the National Institute of Oceanography (NIO) in Goa, told Mongabay-India. “One need not worry about cyclic erosion as erosion during the rough season gets balanced by accretion during the calm season in a year. Progressive erosion is the one that has to be addressed as it is continuous. The reason for progressive erosion needs to be assured through scientific studies and appropriate corrective measures can then be taken.”
The erosion in Valiyathura, Poonthura and Panathura seems to be progressive as the beach was not restored. But in Shankhumugam, the erosion is cyclic and the beach gets restored after the rough season.
Sea walls and breakwaters not ideal
Constructing seawalls has been Kerala’s main defense against the drastic erosion. However, it’s proved to be a failure, and experts say these walls can in fact have an adverse effect.
Seawalls are structures built between the water and the land, usually along the coastline, to stop waves hitting the shore and prevent soil erosion. Of the 590-kilometer (367-mile) stretch of Kerala’s coastline, 310 kilometers (193 miles) have seawalls.
K.V. Thomas, a scientist formerly with the Kerala-based Centre for Earth Science Studies (CESS), told Mongabay-India that seawall construction was, conversely, one of the factors for the erosion. He said erosion during the monsoon was common; but after the rains, the beach doesn’t get restored, all because of the seawall. The sediments that are washed away don’t come back, he said.
He said the erosion in Thiruvananthapuram district began about 30 years earlier in the Panathura and Poonthura coastal areas. These coasts had pozhi, sandbanks between the sea and backwaters, that were opened seasonally to prevent flooding in the nearby Karamana River. “Thereafter, the government started a stable mechanism to open and close the pozhi,” Thomas said. “A wall was constructed from the river extending to the sea. Since then, beach erosion began in the areas where the wall ended.”
He added that sand mining was also prevalent along the coastal areas of Thiruvananthapuram district: “That was also a reason for the erosion.”
According to Thomas, Valiyathura and Shankhumugam are the most affected beaches because both “lie in between a gap of seawalls.”
“The Valiyathura shoreline exists in between two seawalls that end on its south side and another seawall had started from other side where the people lived in between,” he said. “So it caused an elevation of water level in the gap. That is how we lost hundreds of houses in Valiyathura.”
Cyclone Ockhi in 2017, which claimed more than 200 lives in southern Tamil Nadu and Kerala states, is also believed to have exacerbated the problem. “This year the erosion was severe compared to previous years because the damage that happened during Ockhi could not be repaired due to continued depressions in the sea after the cyclone,” Thomas said.
“We have around 590 kilometers of coastline; I don’t think seawall construction produces the desired effect,” said Oommen V. Oommen, former chairman of the Kerala State Biodiversity Board. “Seawalls and breakwaters are not scientific solutions. Putting a barrier in the coast will destroy the ecosystem. It will deepen the sea.”
He also hinted at a larger environmental concern over sourcing quarry stones for the construction of these walls. “Where do we get these quarry stones to build the seawall? It is by destroying the hills of Kerala. So in a way through this unscientific method we are destroying coastal areas as well as the hills,” he said.
‘Leave the sea to itself’
Oommen said there was a need to give space for the sea to expand and contract.
“Leave the sea to itself,” he said. “Forty-four rivers of Kerala drain into the sea. A considerable amount of soil from the Western Ghats accumulates in the sea. Due to this, beach erosion as well as beach formation happens. We should leave the sea to itself, for its expansion or its contraction.”
The focus should instead be on rehabilitating the fishing community away from the sea, he said. “Just one-tenth of the amount spent on seawalls is required to rehabilitate the people in coastal areas. It is we who have to adapt to the conditions of the sea.”
National Fishworkers Forum general secretary T. Peter said the local communities that understood the sea were being pushed away from the shore, and unscientific human interference was causing a disaster.
“Wherever breakwaters are being built on the west coast, issues like soil erosion are happening,” he said. “In my childhood, during monsoon, I remember waves sweeping away the soil from the shore and naturally creating a wall using this soil in the sea. And then in September, the waves calmed down and brought back the soil. But now due to human interference, this doesn’t happen. Because of breakwaters, the soil that is washed away is not coming back.”
Peter agreed that the seawalls were an issue: “When a seawall is built on one shore, the shore nearby will erode.”
Harbors are yet another reason for erosion, he said, warning that the under-construction Vizhinjam port project in Thiruvananthapuram will cause huge damage to the coastal area.
Thomas, who agreed that harbors caused sea erosion, said the Vizhanjam port might not have an immediate effect, although in the long term it would be harmful and negatively impact the coastal ecosystem. He also said there was an immediate need to strengthen beach nourishment to protect the coastal area.
“The way to protect Valiyathura for the time being is to close the gap between the seawalls, even though it is not a permanent solution,” he said. “That is why we need detailed studies to bring a sustainable solution to these issues. We need to study how to restore the sediments in the beach. Beaches should be divided into sub-cells of 5 kilometers [3.1 miles] where beach nourishment takes place. This will not be an overnight process, but a long-term sustainable plan to address erosion.”
Oommen said natural protection was the only way out. “We need to plant trees and plants in the coastal areas that protect our beaches,” he said. “Only natural remedies can solve the issue, not manmade constructions. Coastal vegetation as well as mangrove plantations can hold the sand in the shore.”