Modelling storm surge hazard to mekong delta

Abstract

Climate change has increasingly affected coastal environments and coastal communities. Long-term sea-level rise and infrequent but severe storm surges are expected to cause potential inundation in Mekong delta, the largest delta of Vietnam. This paper presents storm surge modelling along the coast of Mekong delta in the context of sea-level rise. Based on hydro-oceanographic conditions (river discharge, water level, typhoon wind speed) corresponding to given return periods (RPs), the authors use two-dimensional numerical models with nested grids to predict the maximum surge level during a synthetic typhoon that occurs during high tide. The models are calibrated against measured water levels and surveyed surge heights. Computation results show that the maximum water level might reach 4.2 m for the case of 100-year RP. The modelled surge envelope is generally higher than that presented in the Vietnam's standard. The modelling method demonstrates physical links between tide, wind, wave, and surge, and can be applied to other coastal zones.