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Coastal regions of India are prone to sea level rise, cyclones, storm surges, and human-induced activities, resulting in flood, erosion, and inundation, and some of these impacts could be attributed to climate change. Mangroves play a very protective role against some of these coastal hazards. The primary aim of the study was to estimate wave energy attenuation by mangrove vegetation using modeling, and to validate the model results with measurements conducted off Mumbai coast, where a mangrove forest is present. Wave measurements were carried out from 5–8 August 2015 at three locations in a transect normal to the coast using surface-mounted pressure-level sensors in spring tide conditions. The measured data presented wave height attenuation of the order of 52%. Model set-up and sensitivity analyses were conducted to understand the model performance with respect to vegetation parameters. It was observed that wave attenuation increases with an increase in drag coefficient, vegetation density, and stem diameter. For a typical set-up in the Mumbai coastal region having a vegetation density of 0.175 per m2, stem diameter of 0.3 m, and drag coefficient varying from 0.4 to 1.5, the model reproduced attenuation ranging from 49% to 55%, which matches reasonably well with the measured data. Spectral analysis performed for the cases with and without vegetation very clearly portrays energy dissipation in the vegetation area. This study also highlights the importance of climate change and mangrove vegetation.

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A Very Severe Cyclonic Storm "Yaas" developed over the Bay of Bengal (BoB) on May 23, 2021, and crossed over the Odisha coast on May 26 with maximum sustained wind speed of 75 kts. Herein, a pathway has been developed and exempli ed for 'Yaas' through three-stage cyclone-induced hazard tracking. Days before the cyclone formation, Cyclone Genesis Potential Parameter, Sea Surface Temperature (SST) (> 30 0 C) and Tropical Cyclone Heat Potential (anomaly of 40-80 kJ/cm 2 ) indicated a strong possibility of cyclogenesis in the BoB. A Lagrangian Advection Model used for its track prediction with 24-hour lead-time provided an accuracy of ~ 19 km and ~ 6 hour in its landfall location and time. Further, intensity prediction was done using Numerical Weather Prediction model. Geostationary Satellites, INSAT-3D/3DR, were used to visualise cyclone structure.Passing of cyclone had its reverbarations in oceans, which are observed in SST drop of ~ 3 o C, salinity and density increase by ~ 1 psu and ~ 2 Kg/m 3 , respectively. During the period, 23-26 May 2021, the Ekman suction velocity and chlorophyll concentration were found signi cantly high at ~ 5m/day and > 0.5 mg/m 3 , respectively. Forecast of storm surge was found to be between 3.5-4 m at coastal locations. Signi cant wave height was found to be 5.5 to 9.2 m. The coastal inundation forecast for 24 May 2021 provided its quantitative maximum inland extent. Finally, loss of the crop, shery and forest areas by strong winds and inundation/ingress of saline water associated with storm surge were examined using SAR and optical data.