The numerical modelling of storm surges in the Bay of Bengal

Abstract

Abstract A numerical model is developed for the simulation of surges generated by a tropical cyclone in the Bay of Bengal. The analysis area extends from approximately 11°N to 22°N and, in the northeastern sector of the Bay, includes a representation of the Ganges‐Brahmaputra‐Meghna river system in Bangladesh. The extent of the analysis area allows three days of the surge‐generating capacity of a cyclone originating in the southern Indian Ocean to be recorded before landfall at the Bangladesh coast. The incorporation of the river system permits a potentially deep inland penetration of surges originating in the Bay. The model is non‐linear and this allows a determination of the interactive effect between surge and the astronomical tide. Numerical experiments are described that relate to the change in surge response resulting from a change in the cyclone track during the 24 hours preceding landfall. An account is given of the interaction between surge and tide in the Bay and the river system.