广州汛期暴雨频数和强度统计及周期分析

Frequency,Intensity Statistics and Cyclical Analysis of Rainstorm in the Flood Season in Guangzhou

[目的]分析广州汛期暴雨的频数和强度及周期变化。[方法]利用1951～2010年广州市逐日降水资料,采用线性回归分析、相关分析、小波分析等方法,对近60年来广州市汛期暴雨的年际与年代际变化特征进行了分析,并分析了汛期暴雨与年平均温度的关系。[结果]近60年来,广州汛期暴雨量和暴雨日分别以6.23 mm/10a和0.27 d/10a的线性趋势增长,日数(雨量)最多的年份均为2001年,为15 d(1 085.7 mm),最少年份没有暴雨(1990年);广州汛期暴雨量和日数的年际变化均在近20年明显增多;前后汛期暴雨年代和年际变化均存在差异,前汛期趋势增多,后汛期趋势有微弱减少。广州汛期暴雨日数与年平均温度的正相关关系显著,相关系数为0.22,通过α=0.02的显著性水平检验。广州市前汛期暴雨总日数主要存在4.2年左右的年际和52.9年左右的年代际周期变化,后汛期主要存在5.5年左右的年际和18.4年左右的年代际周期变化。[结论]该研究为汛期降水预报提供科学依据。

[Objective] The research aimed to analyze the variations of rainstorm frequency,intensity and period in the flood season in Guangzhou.[Method] Based on the daily precipitation data in Guangzhou City during 1951-2010,the interannual and interdecadal variation characteristics of rainstorm in the flood season in Guangzhou City in recent 60 years were analyzed by using the linear regression analysis,correlation analysis,wavelet analysis and so on.Moreover,the relationship between the rainstorm in the flood season and annual average temperature was analyzed.[Result] In recent 60 years,the rainstorm amount（days） in the flood season in Guangzhou respectively increased with 6.23 mm/10a and 0.27 d/10a linear trends.The most rainstorm days（rainfall） was in 2001 and was 15 d（1 085.7 mm）.There was no rainstorm in the least year（1990）.The interannual variations of rainstorm amount and days in the flood season in Guangzhou obviously increased in recent 20 years.The decadal and interannual variations of rainstorm in the prior and latter flood seasons had the difference.The trend in the prior flood season increased and in the latter flood season slightly decreased.The positive correlation between the rainstorm days and the annual average temperature in the flood season in Guangzhou was significant,and the relative coefficient was 0.22,which passed α=0.02 significance level test.The total rainstorm days in the prior flood season in Guangzhou City mainly had 4.2-year interannual and 52.9-year interdecadal periodic variations.The total rainstorm days in the latter flood season mainly had 5.5-year interannual and 18.4-year interdecadal periodic variations.[Conclusion] The research provided the scientific basis for the precipitation forecast in the flood season.