黄山区汛期小时强降水特征及阈值研究

Impacts of the Characteristics and Threshold of Hour Heavy Rainfall in Huangshan District during the Flood Season

利用安徽省气象信息中心整编的自动站十分钟降水资料数据和基准站分钟降水数据,统计形成黄山区汛期小时降水数据集。通过百分位阈值法计算18个站点的极值,通过GEV参数估计方法计算出黄山光明顶站极端小时降水阈值及其对应的重现期,最后通过降水比例、强降水频次及占比描述了黄山区强降水阈值特征分布。结果表明:整体上看,无论从汛期平均降水比率或强降水占比和频次分布上看,高海拔地区更容易出现降水,黄山景区发生降水的比例相对较高,北部地区发生降水的比例较低,降水时间多寡的南北差异比较明显。从百分位阈值分布上来看,99th百分位阈值分布不均匀,且变化幅度较大,高值中心主要集中在黄山景区,而95th百分位阈值整体分布比较均匀,整体变化幅度不大。黄山光明顶站5、10、20、50、100年一遇的小时降水阈值分别是43.3、49.7、82.4、120.8、163.9 mm/h。重现期越长,其对应的降水强度增长越快。

Based on the ten-minute precipitation data of automatic station and the minute precipitation data of the base station, which is reorganized by the Anhui meteorological information center, the data set of hour rainfall data in Mount Huangshan district during the flood season is counted and formed. The extremes of 18 sites are calculated by the percentile threshold method;extreme value calcula-tion of the 18 sites is received by percentile threshold method;the extreme hourly precipitation threshold of Huangshan Guangding station and its corresponding recurrence period are calculated by the GEV parameter estimation method, Finally, this paper describes the distribution of precipi-tation threshold in Mount Huangshan region by precipitation ratio, heavy rainfall frequency and occupying ratio. The results show that: in general, precipitation in high altitude areas is more likely to occur in areas of high altitude, regardless of the average precipitation ratio or the proportion and frequency distribution of strong precipitation. The proportion of precipitation in Mount Huangshan scenic area is relatively high, and the proportion of precipitation in the northern region is low, the difference between the north and the south of the precipitation time is obvious. From distribution of the percentile threshold, the distribution of 99th percentile threshold is uneven and varies greatly. The high value centers are mainly concentrated in the Mount Huangshan scenic spot, while the dis-tribution of 95th percentile threshold is relatively uniform, and the overall variation is not large. The hour precipitation thresholds of 5, 10, 20, 50 and 100 year at Huangshan Guangding station were 43.3 mm/h, 49.7 mm/h, 82.4 mm/h, 120.8 mm/h and 163.9 mm/h respectively. The longer the precipitation intensity increases, the more rapidly the precipitation intensity increases.