Wayanad Landslide of 2024, India: Interplay of Geological and Climatic Factors

ABSTRACT The 30 July 2024 Wayanad landslide, a catastrophic event in the Western Ghats of India, has been confirmed through field observations as a composite landslide. It initially developed as a rock slide, along structural discontinuities and foliations in the high-grade metamorphic rocks, before evolving into a debris flow. This flow was subsequently impounded at a few places like in narrow gorges, and the impoundment subsequently breached, resulting in a debris avalanche. Vertical and upstream dipping foliations and shear zones, inherent in the rock strata, induced weakness in the rock formation, which was exacerbated by intense rainfall (~572.6 mm in 48 hours), together culminated in this composite landslide. These factors were critical in the initiation and propagation of the landslide. The landslide affected the terrain, covering a length of 8 km, devastated three villages, and killed 252 people, apart from 47 individuals still missing. Thus, this event underscores the complex interplay between geological structures and climatic factors in the occurrence of such devastating landslides, providing valuable insights for future hazard assessments and mitigation strategies in similar terrains.