Abstract
Abstract. Coastal managers face the task of assessing and managing flood risk. This requires knowledge of the area of land, the number of people, properties and other infrastructure potentially affected by floods. Such analyses are usually static; i.e. they only consider a snapshot of the current situation. This misses the opportunity to learn about the role of key drivers of historical changes in flood risk, such as development and population rise in the coastal flood plain, as well as sea-level rise. In this paper, we develop and apply a method to analyse the temporal evolution of residential population exposure to coastal flooding. It uses readily available data in a GIS environment. We examine how population and sea-level change have modified exposure over two centuries in two neighbouring coastal sites: Portsea and Hayling Islands on the UK south coast. The analysis shows that flood exposure changes as a result of increases in population, changes in coastal population density and sea level rise. The results indicate that to date, population change is the dominant driver of the increase in exposure to flooding in the study sites, but climate change may outweigh this in the future. A full analysis of changing flood risk is not possible as data on historic defences and wider vulnerability are not available. Hence, the historic evolution of flood exposure is as close as we can get to a historic evolution of flood risk. The method is applicable anywhere that suitable floodplain geometry, sea level and population data sets are available and could be widely applied, and will help inform coastal managers of the time evolution in coastal flood drivers.
Highlights
One tenth of the world’s population live in the low elevation coastal zone (Lichter et al, 2011), or are exposed as temporary residents due to coastal tourism and industry (Kron, 2008)
There is an urgent need for coastal managers to understand coastal flood risk, the drivers of the risk and how the drivers change over time
In this paper we present a method for assessing the historic exposure of coastal residential populations, and how this has evolved over approximately 200 years for two UK case study sites
Summary
One tenth of the world’s population live in the low elevation coastal zone (Lichter et al, 2011), or are exposed as temporary residents due to coastal tourism and industry (Kron, 2008). There is an urgent need for coastal managers to understand coastal flood risk, the drivers of the risk and how the drivers change over time. Drivers of flood risk include population exposed to flooding, frequency of extreme events and the effectiveness of any flood defences and of any other adaptation. All of these drivers can change over time so a full analysis should include an evaluation of how these drivers evolve both historically and into the future (via scenario analysis). While there are many future analyses of flooding, historic analyses are less common, which misses important empirical insights on what has happened
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call