近10a横江中下游汛期面雨量特征分析

利用2013～2022年横江中下游流域昭通段自动气象站汛期4～10月逐日20～20时降水资料,采用泰森多边形法计算4个子流域逐日面雨量,并对其时空分布特征进行了分析。结果表明:近10a横江中下游汛期降水时空变化特征明显,汛期面雨量平均值为843.3mm,降雨主要集中在５～9月,5月开始有强降水发生,8月最多；各个子流域汛期面雨量强降水平均值为2.4～5.2次,关河流域最易出现强降水,洒渔河流域最少,除洒渔河外,子流域均会出现日面雨量≥60mm以上强降水,其中白水江强降水最大；出现流域性强降水频次为3.4/a,白水江易与洛泽河或关河同时发生强降水,全流域性强降水的可能性不可忽视。

Analysis on characteristics of surface rainfall in flood season in the middle and lower reaches of Hengjiang River in recent 10 years

Based on the precipitation data of Zhaotong section automatic weather station in the middle and lower reaches of Hengjiang River Basin from 2013 to 2022, the daily area rainfall in 4 sub-basins was calculated by using the Tyson polygon method, and its temporal and spatial distribution characteristics were analyzed. The results show that the spatiotemporal variation of flood season precipitation is obvious in the middle and lower reaches of Hengjiang River in recent 10 years. The average area rainfall is 843.3mm. The rainfall mainly occurs from May to September. The average area rainfall of each sub-basin is 2.4 ~ 5.2 times, the Guanhe basin is the most prone to heavy rainfall, and the Sayu River basin is the least. Except Sayu River basin, all sub-basins have heavy rainfall of daily area rainfall ≥60mm, among which the Baishuijiang River has the largest heavy rainfall. The frequency of regional heavy precipitation is 3.4/a, and the Baishui River is easy to have strong precipitation at the same time as the Luoze River or the Guanhe River, so the possibility of regional heavy precipitation can not be ignored.