2008-2020年成都地区盛夏降水时空分布特征

为获得成都盛夏降水的时空分布特征,通过2008—2020年中国自动站与CMORPH降水产品融合的逐时降水资料,分析了成都地区盛夏7月、8月降水的时空分布特征。结果表明:(1)成都地区盛夏平均降水量总体呈西高东低的分布趋势。(2)成都盛夏以夜间降水为主,雨带明显向东传递,降水峰值主要出现在3:00—4:00,并且中东部在午后还存在一个次峰值。(3)小时强降水的降水量和降水频次的贡献率在空间上分布基本一致,最大值区均位于大邑和邛崃的交界处,低值区出现在西部高海拔地区和简阳地区。(4)2013年、2018年、2020年小时强降水的次数明显偏多,这是由于副高异常偏西偏北导致。(5)成都西部地区小时强降水的频次明显多于其他地区,但极值却偏小,成都地区极端强降水事件更容易出现在3:00左右。综上,通过对成都盛夏降水的研究,为该地区降水监测、城市防洪和防灾减灾等提供决策依据。

Temporal and Spatial Distribution of Midsummer Precipitation in Chengdu from 2008 to 2020

In order to analyze the spatial and temporal distribution characteristics of summer precipitation in Chengdu, based on hourly precipitation data from 2008 to 2020, the spatial and temporal distribution characteristics of precipitation of July and August in mid-summer in Chengdu were analyzed. The results show that:(1)the average summer precipitation in Chengdu presented a general trend of high in the west and low in the east;(2)in mid-summer of Chengdu, the precipitation mainly occurred at night, and the rain belt obviously transferred to the east; the precipitation peak mainly occurred from March to April, and there was a secondary peak in the afternoon in the central and eastern parts;(3)the contribution rates of precipitation and precipitation frequency of hourly heavy precipitation were consistent in spatial distribution base, the maximum values were observed in the junction of Dayi and Qionglai, and the low values were found in the high-altitude area of western China and Jianyang area;(4)the numbers of hourly heavy precipitation in 2013, 2018 and 2020 were significantly more than those in 2013, 2018 and 2020, which was caused by the abnormal west-north subtropical high;(5)the frequency of hourly heavy precipitation in western Chengdu was significantly higher than that in other areas, but the extreme value was smaller; the extreme heavy precipitation events in Chengdu were more likely to occur around 3:00. In summary, through the study of Chengdu summer precipitation, it provides decision-making basis for precipitation monitoring, urban flood control and disaster prevention and mitigation.