摘要
明确流域极端降水的变化特征,对于科学应对极端灾害天气,减少极端降水事件造成的危害具有重要意义。采用相对阈值的极端事件辨识方法,基于极点对称模态分解,从降水频率-强度-持续时间角度,对1960—2016年嘉陵江流域的极端降水的趋势、周期、突变进行了研究。结果表明,嘉陵江流域极端降水频率总体趋势无明显变化,但存在较强的波动变化,持续1 d的极端降水频率215.63次/a,当前处于周期上的变化低谷;存在2~3 a、4~5 a、10 a左右3种周期分量,随降水时长振幅波动减小;突变变化明显,约10 a发生一次突变;空间上南多北少。极端降水强度波动变化,持续1 d极端降水的场均强度为45.63 mm,当前处于周期变化的低谷段;存在2~3 a、5~6 a、10~12 a左右的变化周期,长时间持续降水强度波动幅度较大;突变变化较多,约10 a发生一次;空间上呈现中心辐射状分布,强度中心位于流域东南。研究结论可以为应对嘉陵江流域极端降水的防灾减灾提供参考。
Clearing the variation characteristics of extreme precipitation in the basin is of great significance for scientific response to extreme disaster weather and reducing the harm caused by extreme precipitation events. In this paper, the trend, period and mutation of extreme precipitation in Jialing River Basin from 1960 to 2016 are studied from the perspective of precipitation frequency-intensity-duration based on the identification method of extreme events with relative threshold and Extreme-point Symmetric Mode Decomposition. The results show that the overall trend of extreme precipitation frequency in Jialing River Basin has no obvious change, but there is a strong fluctuation. The frequency of extreme precipitation lasting for one day is 215.63 times/a, which is currently in the trough of periodic change. There are three kinds of periodic components about 2~3 a, 4~5 a and 10 a, and the amplitude fluctuation decreases with the precipitation duration. Mutation changes significantly, about 10 a a mutation;more south than north in space. Extreme precipitation intensity fluctuates, the field average intensity of extreme precipitation lasting for one day is 45.63 mm, which is currently in the valley of periodic change;there are 2~3 a, 5~6 a, 10~12 a of change cycle, the amplitude fluctuation decreases with precipitation time;Mutations change obviously, about 10 years occurred once;spatially, it presents a central radial distribution, and the intensity center is located in the southeast of the basin. The research conclusions can provide reference for disaster prevention and mitigation of extreme precipitation in Jialing River Basin.
作者
安文杰
胡旭健
苗蔚
张尚弘
AN Wenjie;HU Xujian;MIAO Wei;ZHANG Shanghong(School of Water Resources and Hydropower Engineering,North China Electric Power University,Beijing 102206,China)
出处
《水利水电技术（中英文）》
北大核心
2022年第12期11-23,共13页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(51979105)。
关键词
嘉陵江流域
极端降水
频率
强度
时空分布
Jialing River Basin
extreme precipitation
frequency
strength
spatial and temporal distribution
