Assessing the vulnerability of coastal infrastructure to sea level rise using multi-criteria analysis in Scarborough, Maine (USA)

Sea level rise and climate change will have widespread impacts on coastal towns and cities, many of which have seen dramatic increases in development over recent decades. In addition to potential private property damage, the critical public infrastructure that supports these regions will become increasingly vulnerable to coastal flooding. This paper describes a straightforward, structured methodology for identifying and prioritizing critical infrastructure vulnerabilities in the coastal community of Scarborough, Maine, USA. The study uses GIS mapping and analysis techniques to identify infrastructure vulnerabilities in a coastal town under three different potential future flooding scenarios. A simple multi-criteria analysis matrix is used to explore the often hard to quantify, multifaceted consequences of infrastructure loss. Numerical scores are attributed to represent the economic, social, health and safety and environmental impacts of coastal flooding, allowing vulnerable locations to be ranked in order of overall importance. The results are summarized in a series of tables, maps and data sheets that convey data in readily accessible formats. High traffic roads, including evacuation routes, and major utility corridors are identified as the most critical vulnerable infrastructure assets in the town. Targeted improvements are recommended in these critical areas to improve system and community resilience to climate change and sea level rise. Our approach makes use of standard techniques, requires limited data and is therefore readily transferable for use in infrastructure planning in other similar communities. The methodology encourages public engagement and education, and the results can be used by the local authorities to pursue external funding opportunities to support investment in proactive infrastructure adaptation. The identification of key system weaknesses will allow future infrastructure investment to be targeted to the most critical areas, and assist in improving emergency response plans.