阳曲县近30年汛期不同等级降水变化特征

Variation Characteristics of Different Grades of Precipitation During Flood Season in Recent 30 Years in Yangqu County

文章通过整理1991年—2020年近30年阳曲国家气象观测站5月—9月汛期逐日降水量,分析汛期降水量变化规律及不同等级降水量和降水日数变化规律,研究表明:1991年—2020年阳曲县汛期年均降水量为348.3 mm,近30年来阳曲县年汛期降水量与年份总体呈上升趋势;阳曲县汛期不同等级平均降水量中以中雨降水量最多,约占汛期降水量的34%,汛期降水量影响顺序为中雨>小雨、大雨>暴雨;阳曲县汛期降雨日数约48 d,小雨降水日数为37.1 d,中雨降水日数为7.6 d、大雨降水日数为2.8 d、暴雨降水日数为0.5 d。汛期不同等级日数占比小雨降水日数占比呈减少的趋势,中雨、大雨、暴雨降水日数占比呈增加的趋势,其中中雨>大雨>暴雨。

This paper sorted out the daily precipitation of Yangqu national meteorological observation station in the flood season from May to September in the past 30 years from 1991 to 2020,and analyzed the variation law of precipitation in the flood season,precipitation of different grades and precipitation days.The research shows that the annual average precipitation of Yangqu County in the flood season from 1991 to 2020 was 348.3mm,and the annual precipitation of Yangqu County in the flood season in the past 30 years has generally increased,Among the average precipitation of different grades in Yangqu County in flood season,the precipitation of moderate rain is the most,accounting for about 34%of the precipitation in flood season.The influence order of precipitation in flood season is moderate rain>light rain,heavy rain>heavy rain,The number of rainy days in Yangqu County in the flood season is about 48 the number of light rain and precipitation days in Yangqu County in the flood season is 37.1,the number of medium rain and precipitation days in the flood season is 7.6,the number of heavy rain and precipitation days in the flood season is 2.8,and the number of heavy rain and precipitation days in the flood season is 0.5.The proportion of days with different grades in the flood season:the proportion of days with light rain and precipitation is decreasing,and the proportion of days with moderate rain,heavy rain and heavy rain is increasing,of which moderate rain>heavy rain>heavy rain.