Since December, residents along Kerala’s Vembanad Lake India’s longest have been battling flood-like conditions in their homes. For Raphel Abraham a local from Edakochi, life has been nothing short of “hell,” as seawater continues to seep in forcing families to abandon their homes or endure prolonged waterlogging.
The culprit? A mysterious sea phenomenon known as ‘kallakkadal’, which translates to “the sea that arrives like a thief.” Though traditionally observed in the pre-monsoon months (April–May), experts now believe that the waves behind kallakkadal swell waves traveling thousands of kilometers across the ocean may no longer follow a seasonal pattern.
Approved by UNESCO in 2012 as a scientific term, kallakkadal is caused by large swell waves formed due to distant storms and cyclonic activity in far-off oceans, including the Atlantic. These waves, often 2 to 6 metres high, travel silently across the seas and crash unexpectedly into India’s western coast, flooding coastal areas.
But this year’s flooding is more intense and prolonged. Even before the kallakkadal season began, water levels in Vembanad Lake have remained high since December, making life miserable for locals. Residents like Rajendran Thavanakkadavu have had to move into rented homes, while many remain trapped without adequate shelter.
In response Kerala state government convened an emergency meeting to address the waterlogging, recognizing it as a climate change-induced disaster. However short-term shelters have failed to comfort those affected. “We want a permanent solution,” Abraham insists.
Experts say climate change is amplifying the problem. Swell waves, once considered a rarity on India coasts are now reported along both eastern and western shores even in neighboring Bangladesh. Rising sea surface temperatures, thermal expansion, and accumulated silt in the shrinking Vembanad Lake have worsened the situation.
Once spread over 365 square kilometers in 1900, the lake has now shrunk to 206.4 square kilometers and its depth has reduced from eight meters to less than three. The silt load of over 400 million cubic meters has dramatically reduced its water-holding capacity, choking its natural drainage.
To complicate things tidal amplitude has increased from 1 meter to 1.6 meters making it harder for the lake to release water into the sea. Experts like Dr. N. Sanjeevan, former director at the Ministry of Earth Sciences, warn that even de-silting could worsen sea intrusion.
The shrinking coastline and vanishing beaches are another cause for alarm. K.V. Thomas the scientist who first identified kallakkadal in 1984, says that coastal erosion disappearing beaches, and loss of sand dunes have paved the way for more frequent and intense flooding.
While better forecasting methods like using altimeter satellite data have improved swell wave prediction, mitigation remains critical. Restoring beaches and rebuilding natural sand dunes could offer a buffer against future surges. For now the residents of Edakochi and surrounding areas wait ankle-deep in uncertainty for real, long-term relief.