Reconstructing coastal flood occurrence combining sea level and media sources: a case study of the Solent, UK since 1935

Abstract

Using newly digitised sea-level data for the ports of Southampton (1935Southampton ( -2005 and Portsmouth on the south coast of the UK, this study investigates the relationship between the 100 highest sea-level events recorded at the two cities and the incidence of coastal floods in the adjoining Solent region. The main sources of flood data are the daily newspapers The Southern Daily Echo, based in Southampton and The News, based in Portsmouth, supported by a range of local publications and records. The study indicates a strong relationship between the highest measured sea levels and the incidence of coastal floods and highlights the most vulnerable areas to coastal flooding which include parts of Portsmouth, Southampton, Hayling Island, Fareham and Cowes. The most severe flood in the dataset resulted from the storm surge events of 13-17 December 1989 when eight consecutive extreme high waters occurred. The data suggest that while extreme sealevel events are becoming more common, the occurrence of flood events is not increasing. This is attributed to improved flood remediation measures combined with a reduction of storm intensity since the 1980s. However, several recent events of significance were still recorded, particularly 3 November 2005 when Eaststoke on Hayling Island (near Portsmouth) was flooded due to high sea levels combined with energetic swell waves.

Coastal Flooding in the Solent: An Integrated Analysis of Defences and Inundation

“…Tidal residuals rarely exceed 1 m; with only a 0.33 m difference between a 1 in 10 and 1 in 1000 year water-level [35]. Coastal floods in the Solent during the 20th and early 21st centuries have been frequent but usually involving small water depths, and with no recorded loss of human life [36].…”

Trends in reported flooding in the UK: 1884–2013

“…Some studies have supplemented the hydrometric flow data with historical sources such as flood marks and descriptions (Macdonald 2006), documentary records (Macdonald and Black 2010) or paleoflood hydrology such as geological records (Costa 1986). More local studies into the frequency and distribution of coastal flooding have used extreme sea level data combined with local records (newspaper reports) to judge when tidal floods have occurred and consider their Consequences (Ruocco et al 2011).…”

Assessment and comparison of extreme sea levels and waves during the 2013/14 storm season in two UK coastal regions

“…duration) of each storm. On the English south coast, consecutive HW events during December 1989 were correlated with the worst flooding on record, despite not generating the most extreme sea levels (Ruocco et al, 2011). Furthermore, weather-ocean-wave-overtopping modelling by Zou et al (2013) describes how magnitude, time and location of sea wall overtopping predictions deviated considerably amongst ensemble members.…”