Modelling seasonality in extreme precipitation A UK case study
Modelling seasonality in extreme precipitation A UK case study
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模拟极端降水的季节性英国案例研究
DOI：
10.1140/epjst/e2009-01093-7
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Rust H
中科院分区：
文献类型：
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作者：
Rust H
我们研究了一个统计模型，描述了英国689个站点极端日降水量的季节变化。月最大降水强度的概率分布模型与广义极值分布（GEV）。我们提出了一个具有季节性变化的位置和尺度参数以及恒定形状参数的整体模型，而不是对每个月的降水最大值分布进行单独建模。这个模型是测试对增强版本的形状参数允许变化。此外，我们比较了一个月和两个月的块长度的模型充分性，并没有发现较大的改进，较长的块长度。根据这个模型，10年和100年的回报水平是以一年中的月份为条件计算的。返回水平的插值到一个完整的覆盖面的英国允许识别的空间模式及其时间演变。这些模式表明，极端降水的不同机制在英国的不同地区占主导地位。
We examine a statistical model for the description of the seasonal variation of extreme daily precipitation at 689 stations across the UK. The probability distribution for monthly maximum precipitation intensity is modelled with a generalised extreme-value distribution (GEV). Instead of modelling the distribution of precipitation maxima separately for every month, we propose an overall model with seasonally-varying location and scale parameters and a constant shape parameter. This model is tested against an augmented version with the shape parameter allowed to vary as well. Furthermore, we compare model adequacy for block length of one and two month and found no major improvements for the longer block-length. Based on this model, the 10 and 100-year return levels are calculated conditioned on the month of the year. The interpolation of return levels to a complete coverage of the UK allows for an identification of spatial patterns and their temporal evolution. These patterns suggest that different mechanisms for extreme precipitation are dominant in different regions of the UK.