近60年福建省极端降水的时空变化特征

目的]探究我国东南沿海地区极端降水变化的新特征，对该地区防灾减灾具有重要意义。方法]以福建省为例，基于1960—2019年67个气象站点逐日降水数据，利用气候倾向率、Mann-Kendall突变检验等方法，分析了极端降水量(R95P)、极端降水频次(R95D)、极端降水强度(R95I)和极端降水贡献率(R95C)4个极端降水指数的时空变化特征，并阐明了极端降水指数与大气环流指数的相关性。结果](1)近60年来福建省R95P,R95D,R95I和R95C呈现出增加趋势，变化率分别为24.90 mm/10 a, 0.34 d/10 a, 0.25(mm/d)/10 a和0.84%/10 a。(2) R95P,R95I和R95C均在1994年以后转为偏多(强)期，而R95D的突变点出现在1993年，由降水日数偏少期转变为偏多期。(3)西太平洋副高强度指数、南海副高强度指数和北半球极涡强度指数与极端降水指数之间有显著的相关性(p<0.05),特别是南海副高强度指数对转折后时段的R95D有显著影响。结论]研究结果对该地区开展极端降水的生态风险评估提供重要参考。

Spatial and Temporal Characteristics of Extreme Precipitation in Fujian Province in the Last 60 Years

Objective]It is important for disaster prevention and mitigation to explore the new characteristics of extreme precipitation changes in the southeast coastal region of China. Methods] Daily precipitation datasets of 67 meteorological stations from 1960 to 2019 were selected, and methods of climate tendency rate and Mann-Kendall test were used to analyze the spatial and temporal variation characteristics of four extreme precipitation indices, including the extreme precipitation(R95P), extreme precipitation frequency(R95D), extreme precipitation intensity(R95I), and extreme precipitation contribution(R95C). Meanwhile, the correlation between extreme precipitation indices and atmospheric circulation indices was also analyzed. Results](1)tR95P, R95D, R95I and R95C had the increasing trend during the last 60 years, and their change rates were 24.90 mm/decade, 0.34 d/decade, 0.25(mm/d)/decade and 0.84%decade, respectively.(2)R95P, R95I, and R95C had abrupt changes around the year 1994, which changed from a relatively low(weak)to a high(strong)period. The mutation of R95D occurred in 1993, changing from a low to high period.(3)There was the significant correlation between the South China Sea Subtropical High Intensity Index, West Pacific Subtropical High intensity index, Northern Hemisphere Polar Vortex Intensity Index and extreme precipitation indices(p<0.05). Particularly, the West Pacific Subtropical High has the significant influence on the R95D after the year of 1994. Conclusion] The results provide a scientific basis for ecological risk assessments of extreme precipitation in Fujian Province under the background of climate change.