2H: Coasts and Urban Planning

Using Dynamic Coast Data to Help our Coastal Cities and Towns Become Sea Level Wise, Larissa A. Naylor, Martin Hurst, Alistair Rennie, Jim Hansom, Freya M.E. Muir, Ria Dunkley, Craig MacDonell

Coastal erosion is expected to become more extensive and accelerate in the coming decades, with the potential to also enhance coastal flood risk. These risks occur both along open coasts where Dynamic Coast 2 data shows increased erosion rates and future risks across Scotland and along currently defended urbanised coasts, where low-lying coastal land was often reclaimed from the sea over the past 150 years. We urgently need to consider how to best redevelop and manage existing housing and infrastructure along these ‘built’ estuaries and coasts to manage the emerging risks andsocietal impacts. The Dynamic Coast 2 project has delivered guidance on mitigation and adaptation for coastal managers, land use planners, communities, land owners and developers in Scotland. A key recommendation is that we need to implement an array of short-term options to enhance resilience whilst and developing and deploying medium to long-term resilience and adaptation using an dynamic adaptive pathways approach. To protect key infrastructure assets we may choose to retain and build higher seawalls and commit society to future long-term costs of maintaining these assets ad infinitum. But for the majority of coastal communities, urban resilience to coastal erosion risk may be best achieved by making space on land now, for the coast and the assets behind to move inland in the future. For redevelopment areas especially, providing accommodation space on land for coastal erosion reduces the future need to manage increased risk by expensive coastal defences and/or by relocating newly built houses, assets and communities inland as climate change impacts accelerate. ​ Today's strategic development planning decisions thus need to be climate-smart and provide physical and policy adaptation space to accommodate future erosion and help society become ‘sea level wise’.

Using Coastal Erosion Disadvantage Maps as a Climate Change and Strategic Urban Planning Tool for Scotland, Ria Dunkley, Craig MacDonell, Larissa A. Naylor, Freya M.E. Muir, James Fitton, Alistair Rennie, Jim Hansom, Martin Hurst

Despite accelerated rates of coastal erosion and growing coastal populations, global understanding of the relative resilience of communities to coastal erosion is limited yet social justice and climate justice are key emerging issues of concern for governments. For the first time in the UK, using Scotland as an exemplar, this work aims to couple anticipated erosion risk with consideration of the social vulnerability of Scotland’s coastal communities, to produce Coastal Erosion Disadvantage maps. A combination of Dynamic Coast erosion data, the latest Census data from 2011, the latest data from the Scottish Index of Multiple Deprivation (2016 & 2020) and academic and policy literature concerning coastal erosion and flooding vulnerability, were used to create a Social Vulnerability Classification Index (SVCI) using a series of deprivation and context-specific  indicators. We report that coastal communities have a slightly higher proportion of more socially vulnerable groups compared with the Scottish average with spatial variations in Coastal Erosion Disadvantage (e.g. East Lothian, South Ayrshire and Argyll & Bute have higher vulnerability). The maps show that under an IPCC “High Emissions Scenario” (HES RCP8.5), and assuming no future maintenance of coastal defences, 37% of the residential property anticipated to be affected by coastal erosion are within the top three SCVI vulnerability categories. In addition, 67% percent of socially vulnerable properties that are anticipated to be at coastal erosion risk by 2050, are currently undefended.  We recommend that this initial assessment is used by planners as a catalyst of further in-depth place-based assessments of social vulnerability to erosion for current and future planned developments in at risk communities, to help society become ‘sea level wise’.