Simulations of Heavy Rainfall from a Tropical Cyclone in Coastal Regions of Vietnam under the Global Warming

The central regions of Vietnam often receive heavy rainfall by tropical cyclones in the Western Pacific. A tropical cyclone with strong winds inflicts direct damage to infrastructure, causing losses to both the economy and human life. Heavy rains from a tropical cyclone also cause substantial destruction. Furthermore, because of global warming, the intensity of rainfall is expected to increase in the future. In this study, a record of heavy rainfall event in the central region of Vietnam from Tropical Cyclone Lekima, which hit Vietnam in 2007, was simulated by a Weather Research and Forecast model (WRF), using an ensemble simulation method. Rainfall variability in future climate scenarios was investigated using numerical simulations based on pseudo global warming (PGW) conditions, constructed using third-phase results of Coupled Model Intercomparison Project multi-model global warming experiments. Under certain future climate scenarios, the intensity of rainfall from Tropical Cyclone Lekima would have been heavier than in the present climate. The simulation results show that maximum six-hourly and total precipitation would increase significantly in the future. The spatial distribution of heavy rain from Tropical Cyclone Lekima would tend to shift from North to Southwest Vietnam. Simulation results suggest that global warming may correlate with a significant increase in rainfall.