柘荣县极端降水事件气候特征分析

Climatic characteristics of extreme precipitation events in Zherong County in recent 57 years

为给政府部门的防灾减灾救灾工作提供科学依据,减少灾害损失,基于1961-2017年柘荣县的降水资料,采用回归分析、相关分析、线性倾向估计和F检验等方法,分析近57 a柘荣极端降水事件的年际变化趋势和气候突变现象.结果表明:年极端降水频次、年极端降水总量、年极端降水强度和年最大日降水量均呈线性增长趋势,其中,年极端降水总量和年最大日降水量呈显著增长趋势;年极端降水频次和年极端降水强度呈不显著增长趋势.累积距平法和信噪比突变检验表明,年极端降水频次的突变转折年份出现在1994年,表现为1994年之前为下降趋势,1994年之后为上升趋势;而年极端降水总量、年极端降水强度和年最大日降水量的突变转折年份均出现在2003年,表现为2003年之前为下降趋势,2003年之后为上升趋势;但各极端降水指数均未达到气候突变的标准,突变不显著.对比分析柘荣极端降水指数与全省平均极端降水指数,表明柘荣"暴雨中心"的主要特征是降水总量大、频次少、降水的极端性特别突出.

Zherong County is the main "rainstorm center" in Fujian Province. It is affected by different degrees of rainstorm disasters every year. In order to provide scientific basis for disaster prevention, mitigation and relief work of government departments in Zherong county and reduce disaster losses, based on precipitation data from1961 to 2017, this paper uses regression analysis, correlation analysis, linear tendency estimation and F-test methods to analyze the interannual variation trend and abrupt climate change of extreme precipitation events in Zherong County in recent 57 years. The results show that the annual extreme precipitation frequency, the annual extreme precipitation total, the annual extreme precipitation intensity and the annual maximum daily precipitation all show a linear growth trend,in which the annual extreme precipitation total and the annual maximum daily precipitation show a significant growth trend. The annual extreme precipitation frequency and annual extreme precipitation intensity show no significant growth trend.The cumulative anomaly method and signal-to-noise ratio mutation test show that the abrupt transition year of annual extreme precipitation frequency occurred in1994, showing a downward trend before 1994 and an upward trend after 1994. However, the abrupt transition years of the total annual extreme precipitation, annual extreme precipitation intensity and annual maximum daily precipitation all occurred in 2003,showing a downward trend before 2003 and an upward trend after 2003.However,each extreme precipitation index does not meet the criteria of climate mutation, and the mutation is not significant.A comparative analysis of Zherong extreme precipitation index and the province′ s average extreme precipitation index shows that Zherong′s "rainstorm center"is characterized by large total precipitation, less frequency and especially prominent extreme precipitation.