Research Projects

Rationale: • In the Sundarbans and Gulf of Kutch, dense rural settlements, and water-dependent livelihoods converge to heighten vulnerability to coastal flooding. • These regions face repeated cyclonic storms, high tidal ranges, and seasonal river discharges that combine to produce complex flood scenarios. • Repeated cyclones and human pressures have led to substantial mangrove degradation, fundamentally altering the dynamics of flood propagation. • There remains a critical gap in understanding the physical mechanisms by which specific mangrove structures, i.e., stem densities, root geometries, and sediment interactions modify surge, tide, and wave energy under extreme events. Objectives and Hypothesis: • The central hypothesis guiding this project is that the spatial architecture and physical properties of mangrove ecosystems exert significant, nonlinear controls on cyclone-driven hydrodynamics, which can be explicitly quantified through field observations and process-based modelling. The objectives are thus multi-fold: • To unravel the physical mechanisms by which mangrove structures alter surge heights, wave energy, flow velocities, and sediment transport under varying hydro-meteorological forcings. • To develop and validate an integrated modelling system (ADCIRC+SWAN+XBeach) that explicitly incorporates mangrove-induced drag and roughness, calibrated with field and oceanographic data. • To combine these physics-based outputs with population, infrastructure, and livelihood data to create composite vulnerability and risk maps that directly inform targeted early warning and adaptation strategies. Methodology: • To address these objectives, we will undertake extensive field campaigns in both the Sundarbans and Gulf of Kutch to map mangrove structures (root diameters, stem densities, canopy profiles) and characterize local sediments. • Simultaneous deployments of ADV, pressure sensors, and wave gauges will capture tidal currents, and wave characteristics. • These datasets will inform spatially distributed drag and roughness parameterizations within the hydrodynamic models. • This foundation will support the development of a coupled ADCIRC+SWAN+XBeach modelling framework. Driven by wind, pressure, and rainfall fields from IMDAA reanalysis (for hindcasts) and ECMWF forecasts (for operational scenarios), the system will resolve how cyclone surge, tides, and river discharges jointly propagate through intricate tidal networks and overland floodplains. • A large ensemble of scenarios combining historical cyclones with synthetic tracks spanning diverse intensities, landfall angles, and tidal phases will be constructed, enabling systematic exploration of how incremental mangrove degradation or restoration alters flood behaviour. • Validation will be achieved through comparisons with newly collected field data and satellite-derived inundation footprints from past events. Outcomes and Significance: • This project will substantially advance fundamental understanding of how mangrove ecosystems interact with cyclone surge, tides, and waves under extreme conditions. • This knowledge is essential for anticipating how continued mangrove loss or targeted restoration could alter coastal flood regimes in the face of climate change. • We will integrate outputs with detailed socio-economic datasets, overlaying predicted inundation fields with layers of population density, critical infrastructure, and livelihood dependencies. • By integrating these models with operational forecast products from ECMWF, we will prototype a real-time early warning system capable of translating atmospheric forecasts into detailed, site-specific flood hazard and risk maps. • This fusion of cutting-edge hydrodynamic science with actionable vulnerability assessments holds immediate promise for informing evacuation planning, climate-resilient infrastructure design, and nature-based adaptation strategies in some of India’s most at-risk coastal communities.