Research

Earth, Atmosphere & Environment Sciences

Title :	Vulnerability of Bay of Bengal coastline to tropical cyclones
Area of research :	Earth, Atmosphere & Environment Sciences
Focus area :	Coastal Dynamics
Principal Investigator :	Dr. Neetu S. , Csir National Institute Of Oceanography
Timeline Start Year :	2020
Timeline End Year :	2023
Contact info :	neetu@nio.org

Details

Executive Summary :	Coastal flooding induced by Tropical cyclones (TCs) is the most devastating coastal disaster. This flooding results from a combination of the storm surge (i.e. the sea-level elevation due to onshore water transport ahead of the storm and smaller inverse barometric effect), strong TC-induced waves and background sea-level variations, including astronomical tides. The Bay of Bengal (BoB) is by far the most vulnerable region to coastal flooding because of densely populated low-lying areas and a shallow continental shelf, which amplifies the surge. As a result, the BoB reports 80% of global TC fatalities, while only hosting 5% of TCs. This exposure to coastal flooding is expected to increase over the coming decades due to coastal population increase and climate change-induced sea-level rise and more frequent intense TCs. Despite these broad societal implications, the understanding of the flooding dynamics in the BoB is still incomplete as most attempts to model TC-induced flooding in the BoB largely relied on case studies, used imprecise bathymetry datasets and/or did not account for the wave setup contribution. To fill that gap, we propose to develop a coupled surge-wave model that uses an improved bathymetry and accounts for the wave contribution and perform dedicated coupled wave-surge model experiments forced with a large number of TCs and validated against an exhaustive water-level observational database. With this setup in hand, the first broad objective of this project is to better understand the flooding dynamics by assessing how waves respond to TCs in the deep ocean, how these waves contribute to the mean elevation in the breaking regime close to the shore and how they interact with the storm surge and tides to induce coastal flooding. The incomplete understanding of the flooding dynamics also explains the absence of a proper risk assessment to TCs-induced flooding in the BoB, hence hampering the development of effective adaptation strategies. With a better understanding of the flooding dynamics, the second broad objective of this project aims at providing a first-of-its- kind risk assessment of TCs-induced flooding around the BoB. The principal investigator previously led an IFCPAR project investigating air-sea coupling under cyclones in the BoB, which was rated Excellent. Gathering a unique blend of BoB TCs, waves and surges dynamics, the current project will allow ground-breaking advances on storm inundation modelling in this region. The resulting risk assessment will provide base level information for coastal management, by contributing to identify the most vulnerable coastal areas in the BoB, for which adaptive measures are most needed.
Co-PI:	Dr. Akhil Valiya Parambil Csir National Institute Of Oceanography,Raj Bhavan Road, Dona Paula,Goa,North Goa-403004, Dr. Suresh I Csir National Institute Of Oceanography,Raj Bhavan Road, Dona Paula,Goa,North Goa-403004
Total Budget (INR):	18,65,120
Publications :	1