Classification of Drought and Flood During Guangdong's Flood Season and Causes of Anomalies
XU Biyu
YE Longming
HOU Zhihan
LIN Xin
YU Xingzhan
Abstract：To provide a reference for drought and flood forecasting during the flood season,this study recalculates the Standardized Precipitation Evapotranspiration Index(SPEI)using data from 86 national me-teorological stations in Guangdong and NCEP reanalysis data from 1973 to 2022.Methods such as Empirical Orthogonal Function(EOF)decomposition and Mann-Kendall test were employed to classify drought and flood patterns during Guangdong's flood season and analyze their causes.The results indicate the following.1)The spatial distribution patterns of drought and flood during Guangdong's flood season can be categorized into three types:province-wide consistency,east-west pattern,and north-south pattern.2)Over the past 50 years,Guangdong's flood season has shown a consistent drying trend,particularly during the 1989-1993 period,where the drying trend was pronounced.3)The main rainfall areas during the flood season are Yangjiang,Jiangmen,and Shanwei;eastern Guangdong is more sensitive to drought conditions,while northern Guangdong is more sensitive to flood conditions.4)The province-wide consistency pattern may be influenced by the intensity of the southwest monsoon,the east-west pattern may be related to the subtropi-cal high and westerly trough,and the north-south pattern may be affected by low-pressure systems in the South China Sea,such as typhoons or monsoon troughs.
Keywords：climatologyflood seasondrought and flood classificationanomalous drought and floodstandardized precipitation evapotranspiration index(SPEI)empirical orthogonal function(EOF)Guang-dong
Publication Date：2025-10-20
Online Publishing Date：2025-10-30(First online date of this platform, not the publication date of the document)
Pages：6( 6-11 )