基于城市下垫面产汇流视角的盱眙县极值雨型和最大径流关系分析

Analysis of the Relationship between Extreme Rain Pattern and Maximum Runoff in Xuyi County Urban Area based on the Perspective of Production Confluence of Urban Underlying Surface

选取江苏省淮安市盱眙县为研究区,通过文献研究法、芝加哥雨型法及统计分析方法,对盱眙县极值降雨雨型和最大径流关系进行研究.结果表明:1957-2020年,年均降水量为1 015 mm,且呈波动上升趋势,主要集中在7-8月,占比40%;年均蒸发量最大值在6月,占比12.7%;1957-2020年,最大日降水量均值为45 mm,其中64年中最大日降水量为1970年7月27日的233.2 mm;在120 min模式雨型中,雨峰系数确定为0.4,降雨强度呈单峰型分布;年径流总量控制率从60%提高到95%,对应的设计降水量从16.3 mm提高到71.5 mm,且设计降水量的增速越快.

Xuyi County,Huai'an City,Jiangsu Province,was selected as the study area,and the relationship between extreme rainfall rain patterns and maximum runoff in Xuyi County was studied by literature research method,Chicago rain pattern method and statistical analysis of data using Excel software.The results show that from 1957 to 2020,the average annual precipitation was 1015mm with a rising wave trend,mainly concentrated in July-August,accounting for 40%;the average annual evaporation was 1335mm,with the annual maximum in June,accounting for 12.7%.from 1957 to 2020,the average value of maximum daily precipitation was 45mm,among which the maximum daily precipitation in 64 years was 233.2mm on July 27,1970.In the 120min model rain pattern,the rainfall peak coefficient was determined as 0.4,and the rainfall intensity has a unimodal distribution.The total annual runoff control rate increases from 60%to 95%,and the corresponding design precipitation increases from 16.3mm to 71.5mm,and the design precipitation increases at an increasing rate.