Assessing coastal vulnerability: Development of a combined physical and economic index

Highlights

• A modified Physical Coastal Vulnerability Index (PCVI) was developed and applied to eleven UK sites.

• A new Fiscal Coastal Vulnerability Index (FCVI) was used to compare and contrast PCVI results.

• PCVI and FCVI results were subsequently integrated into a new Combined Coastal Vulnerability Index (CCVI).

• Indices were used to construct GIS based coastal vulnerability maps.

Abstract

As a consequence of climate change, coastal communities worldwide are subject to increased risk from sea-level rise and more intense storms. Therefore, it is important for coastal managers to have focused site specific data on present and predicted climate change impacts in order to determine shoreline vulnerability. There are few UK studies that characterise coastal vulnerability, while nearly all global work has concentrated on geomorphological and to a lesser extent, socio-economic aspects. In response, the present study developed a new Physical Coastal Vulnerability Index (PCVI) and applied it to eleven UK sites, seven in England, three in Wales and one in Scotland. PCVI results were then compared and contrasted with a new Fiscal Coastal Vulnerability Index (FCVI), which enabled coastal areas to be visually classified in one of four categories to inform relative risk. Both indices were subsequently integrated into a Combined Coastal Vulnerability Index (CCVI). Results showed that Great Yarmouth and Aberystwyth were highly vulnerable, while Llanelli and Lynmouth were least vulnerable, and the importance of integrating both indices is demonstrated by modified overall vulnerability assessments. Therefore, CCVI provides a simple to use shoreline monitoring tool which is particularly suitable for assessment of risk. The indices support coastal planning, including intervention or no active intervention policies, and thereby benefitting a range of stakeholders. CCVI works at local, regional and international scales, and identifies vulnerable locations. Consequently, these indices will inform management strategies to improve coastal resilience under various sea level rise and climate change scenarios.

Introduction

Coastal zones are highly dynamic and are susceptible to natural hazards, due to the diverse climatic changes that are occurring around the world (Zsamboky et al., 2011, Arkema et al., 2013). The world's coastlines have different geographical characteristics that influence the generation of trade and other coastal activities and make significant contributions to the economies of countries (Kantamaneni, 2016a). Increases in coastal disasters, particularly flood events, impose large socio-economic costs, particularly in populated estuaries, low-lying coastal urban areas, and islands, and these are important communal hotspots of vulnerability (Hinkel et al., 2010). Threats to coastlines occur where substantial growth on the land near the sea is affected by shape and biophysical features (Carter, 2013), while Newton et al. (2012) introduced a syndrome-based method of assessing coastal vulnerability that emerged from concerns related to the impacts of climate variations on coastal zones, suggesting that multiple stressors impact coastal systems worldwide in several ways. The impacts of regional and global climate changes, sea-level rise, and weather fluctuations, alongside terrestrial processes, represent serious threats to all coastal communities (Oliver-Smith, 2009, Handmer et al., 2012). Global trends in sea-level rise have an effect on the UK, particularly along the Norfolk and Suffolk coastlines in southeast England, where records show a historic rising trend (Doody and Williams, 2004, Pye and Blott, 2006, Brooks et al., 2012). According to UNEP (2013), the UK coast has been strongly altered, and the UK's shoreline is one of the most degraded of any country in the world. Therefore, coastal vulnerability assessments are very important when consideration is given to the management and future development of coastal regions, both in the UK and elsewhere across the globe.

Considerable literature exists from around the world on geomorphological and physical coastal vulnerability (Gornitz and Kanciruk, 1989, Gornitz, 1990, Gornitz et al., 1994, Abuodha and Woodroffe, 2010, Balica et al., 2012, Kumar and Kunte, 2012, Wang et al., 2014, Pramanik et al., 2016, Nguyen et al., 2016, Islam et al., 2016). However, there are few corresponding studies on socio-economic vulnerability (Cutter et al., 2003, Vincent, 2004, Schröter et al., 2005, Rygel et al., 2006, Hahn et al., 2009). Similarly, there are UK studies (McLaughlin et al., 2002, McLaughlin and Cooper, 2010, Denner et al., 2015, Kantamaneni, 2016a, Kantamaneni, 2016b), but none assess combined physical and economic vulnerability. Therefore, the present study assesses the physical and economic vulnerability of eleven UK sites of varying physical and economic characteristics; the locations chosen from academic articles and reports of flooding and loss. By assessing and integrating each site's Physical Coastal Vulnerability Index (PCVI) and Fiscal Coastal Vulnerability Index (FCVI), analyses will enable the comparing and contrasting of physical, economic and combined vulnerabilities from multiple perspectives, including ranking of the eleven vulnerable UK coastal areas.