Abstract：Based on the daily rainfall data of Yichun National Base Station from 1961 to 2020,meteorological disaster risk survey data,rainstorm daily weather situation field data,Jiangxi WebGis radar puzzle products,historical waterlogging information and other data.This paper makes statistics on the daily characteristics of rainstorm in Yichun urban area are counted and waterlogging analysis is carried out.The results indicate that:The annual average rainstorm days in Yichun urban area are 4.0 days,and the annual average heavy rainstorm days are 0.6 days.The continuous rainstorm for more than two days accounts for 7.4%.There are significant monthly and seasonal distribution characteristics of single wave peak.The annual change shows a sharp decrease in the 1970s and a slow increase in the 1970s.Using the wavelet analysis indicate that the daily high-frequency periodic variation of rainstorm increases from 2～4 years to 4～6 years,and the low-frequency periodic variation characteristics of 14～16 years appear after 2000.The MK test indicate that there is a sudden change in 2018.The weather situation of rainstorm in Yichun urban area mainly includes rainstorm of shear jet in front of trough,rainstorm of Meiyu front,rainstorm of subtropical high edge,rainstorm around typhoon and cold air rainstorm in winter.Doppler radar echoes appear as flocculent,blocky,or short bands,with center intensities often reaching 50～55 dBZ.From historical flood events and short-term heavy rainfall in the past 10 years,it can be seen that rainfall exceeding 150 millimeters in 36 hours is the basic condition for large-scale flood waterlogging.However,for short-term heavy rainfall,the precipitation exceeds 45 millimeters for two consecutive hours,it is prone to serious waterlogging,reaching over 60 millimeters,and the scope of waterlogging will significantly increase.The research results provide a reference for rainstorm forecast in Yichun urban area.
2024, Vol. 41 
