Long-term shoreline dynamics of South Kerala Coast using satellite images

The shoreline experiences significant changes due to human activities and natural processes, resulting in erosion and accretion. Studying the morphology of shorelines is crucial for identifying the causes and impacts of coastal processes along the coast, which helps protect the ecosystem and facilitate future development. This study comprehensively analyses shoreline changes along the Kerala coast from 2000 to 2024, revealing substantial shifts due to frequent cyclones and other natural events. Key findings include significant erosion at Shangumugam, Valliyathura, Punthura, and Edapadu beaches and notable accretion at Thumba, Kochuveli, Vizhinjam, Adimalathura, Pullavila, Karumkulam, and Poovar. The study employs a novel trend analysis approach to evaluate the localized impact of cyclonic events on various coastal locations. Trend analysis from 2000 to 2024, using high-resolution satellite images, identified consistent erosion patterns, particularly after Cyclone Ockhi in 2017 and Cyclone Tauktae in 2021, which caused significant, unrecovered erosion along the Vizhinjam coastline. Regression analysis validates the findings with a high correlation (R² = 0.872 against beach profile data and R² = 0.96 against field data). It is observed that the frequency of cyclonic activity has increased in recent times along the Kerala Coast. The study accentuates Kerala’s increasing vulnerability to natural disasters and the necessity of advanced monitoring techniques for effective coastal management.