Sea level rise risk to critical infrastructures: assessment and adaptation using open-access tools and data

Abstract

Sea level rise is one of the most pressing climate concerns, which is already having an impact on many low-lying islands and coastal communities all over the world. Critical infrastructure and livelihoods in coastal areas are at high risk due to rising sea that increases coastal erosion and flooding. The socioeconomic impact in these areas is expected to increase significantly as a result of global warming based on recent climate projections. Therefore, it is essential to assess the vulnerability and potential damages of the exposed areas and infrastructure, in support of decision-making for risk mitigation and adaptation measures. In this context, a two-level methodology is introduced, to assess the impact of sea level rise on critical coastal infrastructures such as port facilities. Firstly, a physical coastal vulnerability index (PCVI) is adopted, to assess the vulnerability of the study area under current climate change conditions. Secondly, a flood loss assessment approach is employed, to quantify the potential impact of future flood events on infrastructure under various climate change scenarios and return periods using flood depth-damage functions. This methodology is applied to Harwich, a coastal town in southeast England, and a major port for cross-channel ferry and freight traffic. Open access tools are employed to collect and process the required data, i.e. Google Earth, QGIS and open flood maps with climate projections. The PCVI assessment showed an overall low vulnerability under current climate conditions, while the loss assessment for selected infrastructure (railways, roads, and buildings) under flood events with return periods of 25-, 50-, and 100-years would result in losses ranging from £11M to £15M under RCP scenarios 4.5 and 8.5 in 2030, 2050 and 2080. Adaptation strategies to the rapid and uncertain changing climate are grouped in three categories, including protection, adaptation, and accommodation. The choice of an adaptation measure should consider the economic, social, and environmental impact associated with these strategies. The vulnerability and loss assessments facilitate decision-making, toward minimising negative consequences and increasing the resilience of the exposed infrastructure and communities.