Study on the Temporal and Spatial Evolution of Extreme Rainfall in Guangzhou

Abstract

Based on the rainfall data of 17 rainfall stations in Guangzhou every 15 minutes from 2004 to 2019, using a combination of statistical analysis and theoretical analysis, this paper analyzes the temporal and spatial distribution of rainfall in Guangzhou during the interannual and flood seasons, and the intensity and frequency of rainfall. The pattern of change and the characteristics of the “5.22” rainstorm showed that the annual rainfall and rainfall in the flood season in Guangzhou showed an increasing trend in the central urban area, and a downward trend in the northern mountainous and southern coastal areas; the intensity and frequency of rainfall in the central urban area were widespread. In the northern mountainous area and the southern coastal area, the opposite is true; the number of heavy rainstorms with a peak value of more than 20 mm in the central city is increasing, but the duration of the rainstorm is shortening, and the opposite is true in other areas; the peak of “5.22” rainstorm is only 39.5 mm, which is much lower than other central urban areas. The largest rainstorm peak in the history of the station, and the long rainstorm duration is the main cause of waterlogging. It is suggested to adopt the idea of adding underground water storage facilities in same place to temporarily alleviate the urban waterlogging problem.