吴川市1970—2020年降水气候特征

Characteristics of the Rainfall Climatology in Wuchuan from 1970 to 2020

利用吴川市1970—2020年单站降水资料,采用平均化、标准化处理、M-K检验、滑动t检验和Yamamoto检验等统计方法对吴川市的降水气候特征进行分析。结果表明:近51年来吴川市降雨量、降雨日数、暴雨量、暴雨日数、暴雨强度及暴雨贡献率分别以5.22 mm/年、0.33 d/年、4.35 mm/年、0.03 d/年、0.16 mm/年和0.0015%/年的速率下降。吴川市季节降水不均匀,汛期和非汛期的降水差异显著。防灾减灾的重点时间段为6月上旬、7月下旬、8月、9月下旬,暴雨大部分集中在后汛期(7—9月)。吴川市各项降水数据均没有发生突变且呈下降趋势,其中暴雨量和暴雨日数的下降趋势并不明显,而降水量、降水日数、暴雨强度和暴雨贡献率的下降趋势比较明显。

Using the rainfall data from a meteorological station in Wuchuan from 1970 to 2020 and with the statistical methods of averaging,standardization,Mann⁃Kendall test,sliding t⁃test and Yamamoto test,this work analyzes the climatological characteristics of the city's rainfall.The results are shown as follows.For the 51 years of interest,its rainfall amount,the number of rain days,the amount of heavy rain,the number of heavy rain days,the intensity of heavy rain and the contribution rate of heavy rain were all decrea⁃sing by the rates of 5.22 mm/yr,0.33 d/yr,4.35 mm/yr,0.03 d/yr,0.16 mm/yr and 0.0015%/yr re⁃spectively.In Wuchuan,rainfall was unevenly distributed for different seasons with significant differences between rainy and non⁃rainy seasons.Early June,late July,August and late September were the four key periods for disaster prevention and mitigation.Most of the heavy rain concentrated in the annually second rainy season(from July to September).In Wuchuan,no abrupt changes took place in any of the above rain⁃fall data,with an insignificant decreasing trend in the amount of heavy rain and the number of heavy rain days but a significant decreasing trend in the rainfall amount,the number of rain days,the intensity of heavy rain and the concentration rate of heavy rain.