2021~2023年象山不同区域汛期降水日变化特征分析

Diurnal Variation of Flood Season Precipitation in Different Regions of Xiangshan from 2021 to 2023

摘要: 基于象山县2021~2023年汛期逐小时降水资料，分析了象山城区、北部山区、海岛、沿海、中部山区五个区域的降水日变化特征。结果表明：象山县白天降水量略多于夜间，城区与北部日变化特征较为一致，大致呈双峰型；城区降水量日变化最大。北部降水频次明显较高，其余区域差异不大；城区、中部、北部、沿海的降水频次日变化趋势较为一致，大致呈双峰型；象山降水出现在16~21时的频次最高。白天降水强度大于夜间，其中13~17时最大，在汛期服务中，可提醒民众下班路上携带雨具。2024年新版预警信号将提醒预报员关注长历时降水的累积量及小时雨强。

Abstract: Based on the hourly precipitation data of Xiangshan County from 2021 to 2023 during the flood season, the diurnal cycle of precipitation in Xiangshan five regions were analyzed, including urban area, northern area, island, coastal and central area. The results showed that the precipitation in the daytime was slightly more than that at night, and the diurnal cycle of the urban area and the northern area were relatively consistent, roughly with a double peak type. The diurnal variation of precipitation in the urban area was the largest. The precipitation frequency in the northern area was obviously higher, and the difference in the other regions was not significant. The diurnal cycle of precipitation frequency in the urban area, the central area, the northern area and the coastal area was relatively consistent, roughly with a double peak type. The highest frequency of precipitation occurred in Xiangshan from 16:00 to 21:00. The intensity of precipitation in the daytime was greater than that in the night, and the maximum was 13:00 to 17:00. In the flood season service, people can be reminded to take rain gear on the way home. The new warning signal in 2024 will remind forecasters to pay attention to the accumulation of long-lasting precipitation and hourly rain intensity.