Assessing the unintended consequences of structural coastal flood protection

The Environment Agency estimate that nationally there are £150 billion of assets and 4 million people that are currently at risk of coastal flooding, and so it is rated as the second highest possible cause of civil emergency in the UK. Church et al. 2013 suggest that coastal flooding is a growing threat due to accelerating average sea-level rise and possible changes in storminess associated with climate change, exacerbated by continued population growth and development on flood-exposed areas Hallegate et al. 2013 therefore any attempt to understand coastal flood events is of the utmost importance. Throughout the twentieth century, and indeed perhaps presently, hard engineering defences have been the default option for adapting to coastal flooding risk. However, the Committee on Climate Change2016 identify that nationally current levels of flood risk management are considered insufficient; especially with regard to sea-level rise and growing socio-economic and environmental pressures, and so in the context of sustainability, new and proactive approaches for the management of coastal flood hazards are needed that engage with a much wider set of tools and knowledge Wilkinson et al., 2015; Bracken et al., 2016.
Structural defence dominated coastlines not only come with the associated costs of maintenance and upkeep, but numerous scholars Vorogushyn et al., 2017; Hallegate, 2017; Aerts et al., 2018 have noted that the continued upgrading of flood defences can lead to an increased density of infrastructure and higher value assets and goods placed closer to the coastline than otherwise would be there: it creates an increased pressure on the defence, forcing a proactive government to implement expensive upgrades to the defence, often leading to greater density increases and locking in a feedback loop the safe development paradox, whereby paradoxically an increase in defence, may lead to increase in overall risk. Concrete led development appears absolute and generates a feeling of complacency amongst a population, potentially leading to a lack of flood preparedness and responsiveness, and catastrophic consequences of unexpected failures, such as the devastation that hit New Orleans following Hurricane Katrina Kates, et al, 2006. Risk is often quoted as a function of hazard, exposure, and vulnerability, and by reducing hazard a government may inadvertently increase the vulnerability of a population, and so the risk of flooding may actually increase an unintended consequence of structural coastal flood protection.
Therefore, the aim of the project is to develop a multidisciplinary comprehensive understanding of the unintended consequences of flood defences and potential implications on future flood risk management policy choices. The project will be based on a comparative analysis of different case studies and the creation of a socio hydrological model using ABM agent based modelling. It will seek to advise flood agencies and policy makers on unintended, and often unincorporated, social, economic, hydrological, and environmental consequences of coastal flood defences, and the challenges facing the UK, and indeed other coastal countries, in a changing climate.