2013—2020年汕头短时强降水的特征分析

Analysis of the Characteristics of Short-range Intense Rains in Shantou from 2013 to 2020

利用2013—2020年汕头地区35个地面自动区域站逐小时降水资料对汕头短时强降水的时空特征进行分析,结果表明:(1)年平均降水量和年平均降水日数呈从南到北递减的分布特点;(2)后汛期发生特大暴雨的几率高于前汛期;(3)短时强降水的日变化表现为午后易产生短时强降水,其中濠江区和南澳县在06:00—10:00出现的几率也较高;(4)各个级别小时强降水的空间分布呈现以潮南区西南部为高值区,向北递减;(5)西南季风和偏南气流型是易导致当地产生小时极端强降水的天气系统。

Using hourly precipitation data from 35 surface automatic weather stations in Shantou from 2013 to 2020, this work analyzes the spatiotemporal characteristics of short-range intense rains in the area. The results are shown as follows.(1) The annual average precipitation amounts and annual average numbers of rainy days decrease in gradient from the south to the north.(2) The probability for unusually heavy rains to happen is higher in the July-to-September rainy season than in the April-to-June rainy season.(3) For diurnal variation, it is likely for short-range intense rains to take place after midday while the probability is also high between 06:00 and 10:00 for the district of Haojiang and Nan’ao county.(4) For the spatial distribution, hourly intense rains at all levels are the most frequent in the southwestern part of the Chaonan district, which decrease to the north gradually.(5) Southwest monsoons and the pattern of southwesterly airflow are the synoptic systems that are likely to cause extremely intense rains in the local areas.