摘要
利用长江三峡库首宜昌站及库区巴东站1955—2008年分钟降水强度资料,采用广义极值分布和线性矩参数估计方法,拟合两站7个短历时(60min以内)年最大降水量概率分布,推断各历时有关重现期降水极值,计算各历时暴雨频次及年最大降水量气候倾向率,分析各历时降水广义极值分布的参数随时间变化规律。结果表明:宜昌、巴东两站7个短历时年最大降水量采用广义极值分布拟合,其效果较好;两站短历时降水平均值趋势变化不明显,而不同百分位数降水量变化趋势差异较大,其中中位数的降水量呈下降趋势,较高百分位数的降水量增加趋势显著,达20%～30%。
Based on the minute precipitation intensity data of Yichang and Badong Stations in the Yangtze River Three Gorges from 1955 to 2008, the generalized extreme value distribution （GEV） and the L-moment method of parameter estimation are used to fit the seven short-duration precipitation probability distribution of annual maximum precipitation, to infer the short-duration rainfall extreme of return periods, to calculate the frequency of heavy rain and the climate trends affected by annual maximum precipitation, and to analyze the parameter variations of generalized extreme value （GEV） distribution of different short-duration precipitation as a function of time. The results show that （1） it is appropriate to fit annual maximum precipitation of different short-duration of Yichang and Badong stations by using GEV. （2） The trend variations of average short-duration precipitation of above two stations are not obvious. There are more differences among the precipitation trend variations at different percentiles. The short-duration precipitation at the median percentiles decreases and that at the higher percentiles increases significantly.
出处
《暴雨灾害》
2010年第1期38-43,共6页
Torrential Rain and Disasters
基金
国务院三峡工程建设委员会办公室生态环境补偿经费(SX2009-004)
中国气象局华中区域气象中心科技创新团队建设项目共同资助
关键词
短历时
分钟降水强度
广义极值分布
分位数
Short duration
Minute rainfall intensity
Generalized extreme value distribution
Percentile
