| Abstract Submission No. | ABS-3.1-0159 |
| Title of Abstract | Chronicle of Destruction: Geomorphic Mechanisms Behind the Wayanad Landslide of July 30, 2024 |
| Authors | Yunus Ali Pulpadan*, Sajinkumar KS, Srikrishnan Siva Subramanian |
| Organisation | IISER Mohali |
| Address | IISER Mohali Mohali, Punjab, India Pincode: 140306 E-mail: yunusp@iisermohali.ac.in |
| Country | India |
| Presentation | Oral |
| Abstract | This study presents a comprehensive investigation of the 2024 Wayanad landslide, integrating field observations, satellite image analysis, numerical modeling, geotechnical testing, and aerial surveys to reconstruct the failure mechanisms and assess the catastrophic downstream impacts. Our results indicate that the landslide was primarily triggered by a pre-existing crack in the source area, first observed in 2020, within a geologically complex terrain characterized by sheared rocks and structural discontinuities. These inherent weaknesses, compounded by extreme rainfall, played a decisive role in slope failure. Intense water infiltration through cracks and joint sets in the gneissic complex accelerated weathering and erosion, while soil mantling exceeding 30 m further heightened slope susceptibility. Numerical simulations suggest that the debris flow was initiated around 01:00 hrs and peaked at approximately 04:00 hrs on 30 July 2024, reaching maximum velocities of up to 28 m/s. The event mobilized an estimated 5.17 × 10⁶ to 5.72 × 10⁶ m³ of material, ranking it among the largest documented debris flows in India. In the transitional deposition-dominant zone, the debris run-up height reached ~32 m, amplified by repeated damming, entrainment, and topographic factors such as cascades and river sinuosity. These processes collectively caused devastating impacts on downstream infrastructure and settlements. Given the inherent fragility of the terrain and its history of recurrent mass-wasting events, the Wayanad region demands urgent attention, including the establishment of real-time monitoring and early-warning systems to mitigate future risks. |
| Keywords | Wayanad Landslide, Western Ghats, Climate Change, Early Warning, Debris Flow. |