ABSTRACT

Extraordinary flood events occurred recently in northwest England, with several severe floods in Cumbria, Lancashire and the Manchester area in 2004, 2009 and 2015. These clustered extraordinary events have raised the question of whether any changes in the magnitude and frequency of river flows in the region can be detected. For this purpose, the annual maximum series of 39 river gauging stations in the study area are analysed. In particular, non-stationary models that include time, annual rainfall and annual temperature as predictors are investigated. Most records demonstrate a marked non-stationary behaviour and an increase of up to 75% in flood quantile estimates during the study period. Annual rainfall explains the largest proportion of variability in the peak flow series relative to other predictors considered in our study, providing practitioners with a useful framework for updating flood quantile estimates based on the dynamics of this highly accessible and informative climate indicator.

摘要

最近在英格兰西北部发生了特大洪水事件，2004年，2009年和2015年，坎布里亚郡，兰开夏郡和曼彻斯特地区发生了数次严重洪灾。这些聚集的特大事件引发了以下问题：区域可以被检测到。为此，对研究区域内39个测河站的年度最大值进行了分析。特别是，研究了包括时间，年降雨量和年气温作为预测指标的非平稳模型。大多数记录显示出在研究期间明显的非平稳行为，洪水分位数估计增加了多达75％。与我们研究中考虑的其他预测因素相比，年降雨量解释了峰值流量序列中最大的变化率，