Changes of extreme high temperature and heavy precipitation in the Guangdong-Hong Kong-Macao Greater Bay Area

Abstract

The changes of extreme high temperature and heavy precipitation events in the Guangdong-Hong Kong-Macao Greater Bay Area from 1961 to 2019 are analyzed in this paper. Based on the high-resolution climate projection simulations, this study also projects the future risks of heat and flood disasters. The results indicate that hot days, hot nights, heat wave durations, extreme daily maximum and minimum temperature have increased significantly at the rates of 3.6 d/10a, 6.0 d/10a, 2.1 d/10a, 0.23 °C/10a and 0.21 °C/10a, respectively. The heavy and very heavy precipitation days, extreme precipitation amount, maximum 1-day and 5-day precipitation amount have increased by 0.6 days, 0.2 days, 12.5 mm, 0.7 mm and 3.5 mm per 10 years, respectively. All the extreme indices will keep increase at similar rates. In the mid-21st, the area with highest heat and flood risks shows an increase by a factor of 10, mainly located in Guangzhou, Foshan, Dongguan, Shenzhen, Hong Kong and the northern part of Zhongshan. The area proportions of the highest two risk levels of heat and flood disasters will be as high as 66% and 60%, respectively. Considering both high climate risks and urbanization developments, it is necessary to improve the resistance to extremes and enhance the resilience of society to these extreme disasters.