Characteristics and Variations of Precipitation Weather in Binhai County

本文基于滨海县1961~2020年历史气象观测资料，对其降水天气特征展开统计分析。结果显示：滨海县年平均暴雨日数为3.4天，且年际呈微弱增加趋势(0.04天/10年)；60年间7月(76天)、8月(52天)占总暴雨日数62.4%，冬季无暴雨；大暴雨(≥100 mm)集中于5~9月(7月18天、8月16天)，60年共45天；未出现特大暴雨(≥250 mm)；年最大1小时降水量最大值为108.9 mm，年最大日降水量最大值为232.2 mm，均呈上升趋势。此外，滨海连阴雨年平均发生4.8次，每次平均持续6.9天，平均雨量为78.0 mm，日照2.1小时；极端过程最长23天(1962年)，最大降水量419.4 mm (1965年)，最小10.2 mm (1992年)；年次数以0.2次/10年减少，最大总降水量以1.8 mm/10年下降。总而言之，暴雨频次呈微弱上升趋势，极端强度(短时/日降水)显著增强，且向春秋季延伸；大暴雨集中于夏季，特大暴雨罕见；连阴雨事件(春、秋季为主)的发生频率与极端强度均呈减弱趋势，可能与季风系统水汽输送能力变化相关。Based on the historical meteorological observation data of Binhai County from 1961 to 2020, this paper conducts a statistical analysis of its precipitation characteristics. The results show that: the annual average number of rainstorm days in Binhai County is 3.4, with a weak increasing trend interannually (0.04 days per decade). July (76 days) and August (52 days) account for 62.4% of the total rainstorm days in 60 years, and no rainstorms occur in winter. Heavy rainstorm (≥100 mm) is concentrated in May-September (18 days in July and 16 days in August), with a total of 45 days in 60 years. Extreme rainstorm (≥250 mm) has been observed. The maximum values of annual maximum 1-hour precipitation (108.9 mm) and annual maximum daily precipitation (232.2 mm) both show upward trends. In addition, the continuous rainy days in Binhai average 4.8 times per year, lasting 6.9 days on average, with an average rainfall of 78.0 mm and sunshine of 2.1 hours. The extreme process lasted up to 23 days (1962), with the maximum precipitation of 419.4 mm (1965) and the minimum of 10.2 mm (1992). The annual frequency decreases at a rate of 0.2 times per decade, and the maximum total precipitation decreases at a rate of 1.8 mm per decade. In conclusion, the frequency of rainstorms shows a weak upward trend, with significantly enhanced extreme intensity (short-term/daily precipitation) extending to spring and autumn. Heavy rainstorms are concentrated in summer, while extreme rainstorms are rare. The frequency and extreme intensity of continuous rainy events (mainly in spring and autumn) both show a decreasing trend, possibly related to changes in water vapor transport capacity of the monsoon system.