Estimating the evolution of flood risk to coastal populations

The long term evolution of flood risk in a coastal area due to (a) Sea level rise and (b) Population rise is assessed. Historic maps and population data are used to estimate the spatial distribution of the coastal population through time, and extrapolated sea levels are used as a boundary condition in a hydrodynamic flood model to estimate the historic flood exten

An improved database of coastal flooding in the United Kingdom from 1915 to 2016

Coastal flooding caused by extreme sea levels can produce devastating and wide-ranging consequences. The ‘SurgeWatch’ v1.0 database systematically documents and assesses the consequences of historical coastal flood events around the UK. The original database was inevitably biased due to the inconsistent spatial and temporal coverage of sea-level observations utilised. Therefore, we present an improved version integrating a variety of ‘soft’ data such as journal papers, newspapers, weather reports, and social media. SurgeWatch2.0 identifies 329 coastal flooding events from 1915 to 2016, a more than fivefold increase compared to the 59 events in v1.0. Moreover, each flood event is now ranked using a multi-level categorisation based on inundation, transport disruption, costs, and fatalities: from 1 (Nuisance) to 6 (Disaster). For the 53 most severe events ranked Category 3 and above, an accompanying event description based upon the Source-Pathway-Receptor-Consequence framework was produced. Thus, SurgeWatch v2.0 provides the most comprehensive and coherent historical record of UK coastal flooding. It is designed to be a resource for research, planning, management and education

Spatial and temporal analysis of extreme sea level and storm surge events around the coastline of the UK

In this paper we analyse the spatial footprint and temporal clustering of extreme sea level and skew surge events around the UK coast over the last 100 years (1915-2014). The vast majority of the extreme sea level events are generated by moderate, rather than extreme skew surges, combined with spring astronomical high tides. We distinguish four broad categories of spatial footprints of events and the distinct storm tracks that generated them. There have been rare events when extreme levels have occurred along two unconnected coastal regions during the same storm. The events that occur in closest succession (< 4 days) typically impact different stretches of coastline. The spring/neap tidal cycle prevents successive extreme sea level events from happening within 4-8 days. Finally, the 2013/14 season was highly unusual in the context of the last 100 years from an extreme sea level perspective

A user-friendly database of coastal flooding in the United Kingdom from 1915–2014

Coastal flooding caused by extreme sea levels can be devastating, with long-lasting and diverse consequences. Historically, the UK has suffered major flooding events, and at present 2.5 million properties and £150 billion of assets are potentially exposed to coastal flooding. However, no formal system is in place to catalogue which storms and high sea level events progress to coastal flooding. Furthermore, information on the extent of flooding and associated damages is not systematically documented nationwide. Here we present a database and online tool called ‘SurgeWatch’, which provides a systematic UK-wide record of high sea level and coastal flood events over the last 100 years (1915-2014). Using records from the National Tide Gauge Network, with a dataset of exceedance probabilities and meteorological fields, SurgeWatch captures information of 96 storms during this period, the highest sea levels they produced, and the occurrence and severity of coastal flooding. The data are presented to be easily assessable and understandable to a range of users including, scientists, coastal engineers, managers and planners and concerned citizens

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Understanding defence failures and coastal flood events: a case study approach

Extreme sea level events are a current global threat, whilst sea-level rise (SLR) and climate change over the 21st century will increase the frequency and severity of flooding in most coastal regions. Numerical model simulations can help to understand and predict coastal floods (e.g. flood mapping and forecasting) but in comparison to flood sources (waves and water levels) coastal flood pathways (defence failures and inundation) are presently less integrated within these models. This thesis develops and demonstrates a methodology to rapidly simulate and understand the consequences of coastal flood events, with an emphasis upon regions where the risks of flooding are not well understood and could change quickly with SLR. The Solent on the south coast of England is the case study, and is prone to frequent flooding. This region is currently differentiated from the UK east and west coasts by experiencing smaller storm surges, and is characterised by undefended sections of shoreline and small floodplains. Within the Solent is Portsmouth, a city of national flood significance (only London and Hull contain more people considered at risk of coastal flooding in the UK). However, life threatening floods have not occurred in living memory. An integrated modelling approach is developed, coupling loads and defence failures with two-dimensional simulations of floodplain inundation. Observations collated from a real storm surge and flood event are shown to generate a validation data set, which indicates that this model can predict floodplain water levels to a good level of accuracy, whilst highlighting implications of such data collection. Solent-wide analysis includes simulations of hypothetical coastal flood events based upon scenarios that cover the full range of coastal loadings (realistic waves and water levels) and defence failures (overflow, outflanking, overtopping and breaching). More detailed case-studies are also applied at two sites within the region (including Portsmouth). This analysis generates peak flood water depths and an overview of impacts across this spectrum of possible floods.This research improves the existing knowledge of coastal flooding in the case study, and highlights a number of generic concepts that should be applied to others. For example the combination of flood simulation methods with real flood event analysis is essential for optimising the interpretation of model outputs whilst supporting inferences about flood consequences associated with extreme loading events (including how these may change with SLR). Simple methods estimated that &gt;24,000 properties are within a 1 in 200 year flood event outline; and incorporating defence failures, flood dynamics, validation and detailed case studies substantially refine the assessment of places likely to experience damages. Breach defence failures generate the worst flood impacts, although in the Solent this failure mechanism is presently less of a threat than outflanking, overflow and wave overtopping. The modelling system includes easily interpreted outputs, whilst being computationally fast; therefore with potential applications including supporting land-use and defence planning, and real-time flood forecasting and warning

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

This paper demonstrates a methodology for integrating existing models for the rapid simulation of coastal flood events across a large and varied case study area on the UK south coast. Following validation against observations from real coastal floods, synthetic events driven by realistic waves and water levels and the full range of failure mechanisms were modelled for a range of loadings to generate peak flood water depths and an overview of impacts across this spectrum of possible floods. Overtopping is relatively important compared to breaching as coastal floodplains are small. This modelling system supports multiple potential applications, such as planning flood warnings, coastal defence upgrade, and land use, including under sea-level rise. The concepts drawn from this study are transferable to similar coastal regions

Understanding a coastal flood event: the 10th March 2008 storm surge event in the Solent, UK

Extreme sea-level events (e.g. caused by storm surges) can cause coastal flooding, and considerable disruption and damage. To understand the impacts or hazards expected by different sea levels, waves and defence failures, it is useful to monitor and analyse coastal flood events, including generating numerical simulations of floodplain inundation. Ideally, any such modelling should be calibrated and validated using information recorded during real events, which can also add plausibility to synthetic flood event simulations. However, such data are rarely compiled for coastal floods. This paper demonstrates the capture of such a flood event dataset, and its integration with defence and floodplain modelling to reconstruct, archive and better understand the regional impacts of the event. The case-study event comprised a significant storm surge, high tide and waves in the English Channel on 10 March 2008, which resulted in flooding in at least 37 distinct areas across the Solent, UK (mainly due to overflow and outflanking of defences). The land area flooded may have exceeded 7 km2, with the breaching of a shingle barrier at Selsey contributing to up to 90 % of this area. Whilst sea floods are common in the Solent, this is the first regional dataset on flood extent. The compilation of data for the validation of coastal inundation modelling is discussed, and the implications for the analysis of future coastal flooding threats to population, business and infrastructure in the region

Spatial And Temporal Analysis Of Extreme Sea Level And Storm Surge Events Around The Coastline Of The Uk

In this paper we analyse the spatial footprint and temporal clustering of extreme sea level and skew surge events around the UK coast over the last 100 years (1915-2014). The vast majority of the extreme sea level events are generated by moderate, rather than extreme skew surges, combined with spring astronomical high tides. We distinguish four broad categories of spatial footprints of events and the distinct storm tracks that generated them. There have been rare events when extreme levels have occurred along two unconnected coastal regions during the same storm. The events that occur in closest succession (\u3c4 days) typically impact different stretches of coastline. The spring/neap tidal cycle prevents successive extreme sea level events from happening within 4-8 days. Finally, the 2013/14 season was highly unusual in the context of the last 100 years from an extreme sea level perspective

An Improved Database Of Coastal Flooding In The United Kingdom From 1915 To 2016

Coastal flooding caused by extreme sea levels can produce devastating and wide-ranging consequences. The \u27SurgeWatch\u27 v1.0 database systematically documents and assesses the consequences of historical coastal flood events around the UK. The original database was inevitably biased due to the inconsistent spatial and temporal coverage of sea-level observations utilised. Therefore, we present an improved version integrating a variety of \u27soft\u27 data such as journal papers, newspapers, weather reports, and social media. SurgeWatch2.0 identifies 329 coastal flooding events from 1915 to 2016, a more than fivefold increase compared to the 59 events in v1.0. Moreover, each flood event is now ranked using a multi-level categorisation based on inundation, transport disruption, costs, and fatalities: from 1 (Nuisance) to 6 (Disaster). For the 53 most severe events ranked Category 3 and above, an accompanying event description based upon the Source-Pathway-Receptor-Consequence framework was produced. Thus, SurgeWatch v2.0 provides the most comprehensive and coherent historical record of UK coastal flooding. It is designed to be a resource for research, planning, management and education