海口市近年短历时暴雨演变特征分析

Analysis on Evolution Characteristics of Short Duration Rainstorm at Haikou City in Recent Years

城市内涝与短历时暴雨有重要关系,为揭示城市暴雨内涝成因,选取海口站1951年—2012年逐时降雨资料,通过趋势线、小波分析、Mann-Kendall趋势检验、集中度等方法对海口市年最大1h降雨序列和暴雨频次进行统计分析。结果表明,海口市年最大1 h、3 h、6 h降雨量均呈增加趋势,且时段越长增加越明显,最大1 h降雨量存在17 a时间尺度上的变化周期,1 h降雨量≥20 mm、30 mm、40 mm的暴雨次数呈不同程度增加趋势,但增加幅度不明显。短历时暴雨次数呈现双高峰,6月和9月为高发时期,一天中短历时暴雨多发生在下午时段。

Urban waterlogging is greatly related to the short duration rainstorms. In order to understand the causes of urban rainstorm waterlogging,based on the hourly precipitation data at Haikou station during the period of1951—2012,the characteristics of the rainstorms in Haikou city were analyzed from the aspects of trend line,wavelet analysis,Mann-Kendall trend method,concentration degree,etc. The results showed that the annual maximum precipitation of 1 h,3 h,6 h were increasing,and the array of 6 h increased more obviously. There existed a periodicity of 17 a timescale of the annual maximum 1 h precipitation. The frequency of rain intensity ≥20mm / h,30 mm / h,40 mm / h increased at different rate in a small range. The frequency of rainstorm occurring in June and September was much higher than the other months. and mostly happened in the afternoon of the day.