1961-2014年广东汛期小时强降水的日变化特征

The characteristics of diurnal variations of hourly heavy precipitation in flood seasons in Guangdong during 1961-2014

利用1961-2014年广东32个地面气象观测站逐小时降水资料,分析了广东小时强降水的降水量、降水频次和降水强度在整个汛期以及前、后汛期的日变化特征和空间分布差异。结果表明,广东区域平均的汛期小时强降水的降水量、降水频次的峰值都是出现在下午16时,次峰值出现在上午8时,而小时强降水的强度日变化不明显。广东汛期小时强降水量和降水频次的峰值分布存在区域差异,南部沿海峰值出现在早晨(6-9时)和中午(10-13时),雷州半岛和其余地区出现在下午(14-20时)。小时强降水的强度峰值在白天和夜晚都可以出现。前、后汛期小时强降水量日峰值振幅存在3个大值中心,分别位于西部的罗定,东部的五华和北部的南雄、连平。小时强降水频次日峰值振幅总体呈从沿海向内陆增加的趋势,而强度日峰值振幅区域差异小。

The characteristics of diurnal variations in amount,frequency and intensity of hourly heavy precipitation in flood seasons,including the first and second flood seasons,and the spatial distribution were studied based on the hourly precipitation data from 32 meteorological observational stations in Guangdongduring 1961-2014.The results show that the peak of hourly heavy precipitation amount and frequency occurred at 16:00,the second peak occurred at 08:00,but the intensity diurnal variations of heavy precipitation were not obvious.There were regional differences at the peak of hourly heavy precipitation amount and frequency in flood seasons.The peak occurred in the morning(06:00 to 09:00)and at noon(10:00 to 13:00)in southern coastal areas,in the afternoon(14:00 to 20:00)in Leizhou Peninsula and the rest of Guangdong.The peak of hourly heavy precipitation intensity occurred on day and night.There were three high-value centers of the peaking amplitudes of hourly heavy precipitation amount during the first and second flood seasons,located in western Lauding,eastern Wuhua,northern Nanxiong and Lianpin.The peaking amplitudes of hourly heavy precipitation frequency showed increasing trend from coastal areas to inland,but there was little regional difference of the peaking amplitudes of hourly heavy precipitation intensity.