Characteristics Analysis of Extremly Severe Precipitation Based on Regional Automatic Weather Stations in Guangdong
Based on the hourly precipitation data of more than 2000 regional automatic weather stations during 2003-2017 in Guangdong， the characteristics of the annual and monthly variations of extremely severe 〖JP2〗precipitation with different durations in Guangdong were ana〖JP〗lyzed. On this basis, the spatiotemporal distributions of the frequency of extreme precipitation in the flood season from April to September were analyzed. The results showed that there are obvious differences among the annual frequency variation trends of extremely severe precipitation with different durations in Guangdong in the last 15 years. The frequency of 24 h precipitation tends to decrease in the annual, the first and the second flood seasons but those of the 3 h and 1 h precipitation increase. The frequency of 1 h extremely severe precipitation shows a significant increase in the annual and the second flood season. May-June is 〖JP2〗the most prone period for extreme precipi〖JP〗tation in Guangdong, whose frequency is mainly found in Yangjiang, Jiangmen and Maoming in the southwest of Guangdong, Guangzhou and Qingyuan in the central and northern parts, as well as Shantou and Jieyang in the east of Guangdong. The extremly severe precipitation in the second flood season is mainly seen in the southcentral region, especially in the southern coast of Guangdong. The number of extremely severe precipitation for 1 h shows an increasing trend in the Pearl River Delta, Xinyi of Maoming and Gaozhou, while the trend for most of the eastern Guangdong decreases. Terrain and atmospheric circulation may be the important factors for the frequency center of extremely severe precipitation in Guangdong.