Numerical Simulation of Storm Surge Using Explicit Finite Element Model for Nivar Cyclone

East coast of India is more prone to the cyclones. The major damages caused by the cyclones are due to the effect of storm surges, the temporary rise in sea level due to storm. They pose more risk to the coastal population with unexpected flooding. Hence, predicting the surge along the coast is important for providing early warnings to evacuate people living along the coastal villages. This helps to take precautionary measures to minimise the damages caused by the cyclones. This study desires to focus on hazard due to cyclone along the Tamilnadu coast. One of the recent cyclones, cyclone Nivar, is considered for the study. Very Severe Cyclonic Storm Nivar hit Tamilnadu coast in late November 2020. The present numerical model is developed by solving the Shallow Water Equation (SWE) based on an explicit finite element scheme. The study domain is discretized with 9- noded unstructured rectangular grids. The integration over an element is carried out by using two-dimensional Simpson's rule of integration. Solutions at each time is obtained explicitly as the system of equations is uncoupled. The element type along with the integration procedure forms an explicit scheme. When compared with the other implicit finite element schemes-based surge models, the present numerical model is computationally efficient. Thus, early predictions from time to time based on the track of the cyclone is possible due to lesser computational time. The precise cyclone track of Nivar, obtained from National Oceanic and Atmospheric Administration (NOAA), is used to simulate the flow field associated with the storm. The peak surge of about 0.64 m is observed near Marakanam and negative surge is witnessed near Nagapattinam.