基于小时降水资料研究广东省降水分布特征

基于2001-2018年广东省86个国家自动气象站逐小时降水资料，分析了广东省不同历时降水的时空分布特征.结果表明：1）除粤北山区外，基本符合年均降水时数越多，累积降水量越大的规律.年均小时降水强度从南部沿海向北部内陆呈减弱趋势.2）汛期降水事件以短历时为主，占全年降水事件65.3%；累积降水量上，长历时降水量占汛期56.7%.前汛期短历时降水多发生在粤西；中历时降水多发生在珠三角两侧和粤西北地区；长历时降水多发生在粤东和粤北地区.后汛期短历时降水多发生在内陆，出现频次自西北向东南递减；中历时降水分布不均；长历时降水多发生在沿海.3）汛期降水时数日变化呈双峰型变化特征，小时降水强度日变化呈单峰型变化特征.小时降水强度峰值易出现在下午的站点多分布在内陆，小时降水强度峰值易出现在下半夜至上午时段的站点则多分布在沿海、部分山区和珠三角地区.

Characteristics of precipitation distribution in Guangdong province based on hourly rain-gauge data

The spatiotemporal distribution characteristics of different duration precipitations in Guangdong province were analyzed based on the hourly rain-gauge data from Guangdong''s 86 National Weather Stations for period of 2001-2018.Results show that the accumulated precipitation would probably rise with the increase of averaged annual precipitation hours in most area of Guangdong,except in northern mountainous area.Annual hourly precipitation intensities show a decreasing trend from the southern coastal area to the northern inland area.Short duration precipitation is the main precipitation type in flood seasons,accounting for 65.3% of the annual precipitation events.While long duration precipitation contributes more (56.7%) to the annual accumulated precipitation.In the pre-flood seasons,short/moderate/long duration precipitations mostly occur in west/both sides of the Pearl River Delta and northwest/east and north of Guangdong,respectively.While in the post-flood season,short duration precipitation mostly occurs in Guangdong''s inland area,with frequencies decreasing from northwest to southeast;moderate duration precipitation is unevenly distributed,and long duration precipitation mostly occurs in coastal area.In flood seasons,a two-peak pattern presents in diurnal variation of precipitation hours,and a single peak pattern inhabits in the diurnal variation of hourly precipitation intensity.The peak values of hourly precipitation intensities tend to occur in afternoon in inland area,or in time after midnight till next morning in areas along coast,some mountainous areas and the Pearl River Delta.