南宁市不同历时降水结构的多时间尺度研究

Analysis of multi-time scales of precipitation pattern at different durations for Nanning city

为研究不同历时降水事件的结构及变化趋势,借助小波分析的时频多分辨功能,从降水历时角度出发,将1971—2012年南宁市国家级地面气象站逐小时降水观测数据分为1~3 h,4~6 h,7~10 h,10 h以上4个历时,分析其多尺度周期变化。结果表明:11~3 h,4~6 h,7~10 h,10 h以上降水次数时间尺度的主周期分别在28,27,29和11年左右,7 h以下降水次数周期变化明显大于7 h及以上。24个历时降水量的主周期分别在28,26,29和12年左右,除7~10 h外,其他历时降水量周期变化都很明显,正负相位交替变化十分明显。3根据分析结果预测,在未来2年内,除4~6 h降水量外,其他历时的降水次数及量都将呈负相位趋势。分析不同历时降水结构的周期变化规律可为深入探索区域降水循环变异规律提供依据。

In order to study the patterns and changing trends of different duration precipitation events, by using the time-frequency multi-resolution of wavelet analysis functions, the time-frequency multi-resolution function of the wavelet analysis was applied to this study. And the hourly rainfall observation data obtained from the Nanning National Ground Meteorological Station from 1971 to 2012 were divided into four durations： 1 -3 hours, 4-6 hours,7 -10 hours and more than 10 hours from a precipitation duration point of view, which was used for analyzing the multi-scale cycle changes. The analysis results show that：① the major periods of 1-3 hours,4-6 hours,7-10 hours and more than 10 hours time scales of the precipitation are respectively in 28,27,29,11 years or so; ②the major periods of the four precipitation durations are 28,26,29,12 years or so, except for the 7-10 hours,others have a very significant change in the precipitation durations, the positive and negative phases of the change are very remarkable;③ from the analysis results it can be predicted that in the next 2 years, the precipitation frequencies and precipitation of other durations will have a negative phase trend in addition to the 4 - 6 hours precipitation. The periodic variation law of the precipitation patterns of different durations can provide a basis for further exploring and analyzing the regional water cycle variation.