SEASONAL VARIATION OF FLOOD ESTIMATES IN THE UK

Flood is one of the most common and significant natural disasters in the world. Over recent decades, accelerated population growth and changes in land use patterns have resulted in increased human vulnerability to floods. Flood estimates are essential for a range of engineering design and planning purposes, including hydraulic structures construction, flood-plain management and flood risk mapping. Even though accurate flood estimates can reasonably reduce potential flood risk by improving the reliability of flood mitigation methods, previous research indicates that conventional methods for flood estimation in the UK still contain uncertainties. This study analyses the seasonal variation of flood estimates at 62 catchments distributed throughout the UK aiming to provide new knowledge and information for improving flood estimation in the UK. The flood seasonality has been investigated from hourly river flow records by using Generalised Logistic (GL) flood frequency curves derived from L-moments. The results indicate that the monthly variation in index flood, parameter k and p for the GL flood frequency curves can reflect a distinct seasonality in river flooding of most parts in the UK. The general trend is that the flood risk is high in winter, and low in summer.