Long-term change of tropical cyclones activity and its potential impacts on Vietnam

Tropical cyclones (TCs) are the most dangerous climatic events in Vietnam. Recently, most of the studies have focused on TCs frequency and intensity, yet the rainfall events caused by them have not been got adequate attention. We show here the long-term change of TCs activity developed in both the South China Sea and the Philippines Sea and estimated its potential impacts during the period of 1977 – 2016. The trend analysis reveals that TCs have not shown obvious variability in numbers and destructiveness ability, whereas the TCs-induced rainfall events and its spatial distribution exhibit more complex patterns in different parts of Vietnam. For example, increasing rainfall amounts in the northern part is likely caused by TCs despite the fact that the TCs frequency did not exhibit much of significant changes. Evaluating rainfall caused by TCs activity is of great practical significance for Vietnam. Our findings suggest that in addition to the TCs frequency and intensity, TCs-induced rainfall events should be considered and included in future preparedness and response plans both on regional and national scale.