01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-05-0070 |
| Title of Abstract | Causative mechanisms of coastal flooding due to Kallakkadal events along the southwest coast of India |
| Authors | Adithyanarayanan A*, Remya PG , Ratheesh Ramakrishnan, Roshyal Joy , Prakash Mohanty |
| Organisation | INCOIS |
| Address | Quarters B12,INCOIS Hyderabad, Telangana, India Pincode: 500090 E-mail: a.ajaykumar-rf@incois.gov.in |
| Country | India |
| Presentation | Oral |
| Abstract | Sudden coastal flooding events known as kallakkkadal affect the southwest coast of India without any apparent local weather triggers, often catching communities off guard. These events are primarily driven by long-period ocean swells originating in the Southern Ocean, which travel vast distances to reach the Indian coastline. This study investigates the hydrodynamic mechanisms behind three Kallakkadal events by linking atmospheric conditions in the Southern Hemisphere with nearshore wave processes. Cut-Off Low systems forming south of 30°S were identified as the primary drivers, generating strong, sustained winds over large fetches that produced energetic swell waves. Using WAVEWATCH III and XBeach models, we simulate the swell propagation and its transformation into infragravity waves , which play a central role in wave setup and coastal inundation. The most severe flooding was observed when IGWs amplified and broke nearshore, especially over gently sloping bathymetry, enhancing wave setup and flood intensity. This combined modelling approach helps trace the complete pathway from atmospheric disturbance to coastal flooding, offering insights into the dynamics of Kallakkadal events. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Kallakkadal,Cut Off Low,Swells,Infragravity waves |
| For Awards | no |