Communities in Galway and Dublin were identified as some of those most exposed to climate-related hazards, a new map developed by researchers at University College Cork has shown.
More than 20,000 people in Dublin and 9,971 people in Galway City live within 500 metres of coastline classified as “Very High Exposure”, the study showed.
High exposure areas in Dublin included Sandymount, Blackrock, Clontarf, Sutton and Baldoyle.
The UCC researchers created the first national map showing the coastal exposure to climate hazards around Ireland.
The map takes into account rising sea levels and storm surges and identifies stretches of coastline facing the greatest pressures from coastal erosion and flooding.
The map is part of a study which developed the Coastal Exposure Index for Ireland, which provides what researchers described as “a consistent national-scale assessment of exposure around Ireland’s coast”.
The index also identifies areas where people, cultural heritage and other coastal assets are particularly exposed, the UCC researchers said.
The research assessed approximately 8,575km of Ireland’s coastline at 250-metre intervals.
It uses 30 years of wind and wave data with information on sea-level rise, storm surges, shoreline type, coastal relief and natural habitats.
Co Mayo is listed as having the coastline with the greatest extent of “Very High Exposure” at 414.5km, while Co Galway has the highest length of both “High Exposure” at 330km and “Moderate Exposure” at 297km.
On the other end of the scale, the Cork coastline had the greatest length classified as “Low Exposure” at 435km and “Very Low Exposure” at 485km.
The researchers said this trend largely reflected Cork’s “extensive elevated, rocky shoreline, which is less vulnerable to coastal hazards than low-lying sandy and sedimentary coasts”.
However, significant areas of “Very High Exposure” remain in Co Cork, including near low-lying coastal settlements of Castletownbere, Cobh, Garryvoe and Youghal.
The study also showed that many coastal heritage sites face “Very High Exposure” to climate hazards.
Raths, promontory forts and ancient coastal burial grounds are among the heritage sites located in areas exposed to coastal erosion, flooding and storm impacts.
Some 1,797 cultural heritage sites were within “Very High Exposure Zones”, out of 8,871 sites located within 500m of the coast.
Many of these affected sites were concentrated on the west coast, researchers said.
Significant exposure was identified on the uninhabited Inishmurray island in Co Sligo, which contains 132 registered monuments.
Natural habitats ‘vital’ to defend against climate hazards
The study also showed that natural habitats provided a “vital protective defence” against climate hazards for both communities and cultural heritage.
Sand dunes, saltmarsh, machair and seagrass were identified as having the potential to reduce exposure along 38% of Ireland’s coastline.
Researchers said these habitats lessen the intensity of wave impact, stabilising shorelines and adapting to sea level rise.
The study cites Dublin’s Bull Island as an example of this protective function as it acts as a natural buffer to wave energy.
Study lead Kevin Walsh said the research presents, for the first time, a consistent picture of relative climate exposure right around Ireland’s coastline.
“What is particularly clear is that exposure varies considerably from place to place, meaning effective adaptation must take account of local coastal conditions.
“Our findings underline the significance of Ireland’s natural coastal habitats as a critical line of defence against climate hazards.
“Dunes, saltmarshes, machair and seagrass can help protect our coastline, communities and heritage from growing climate pressures.
“Protecting and restoring these habitats must be a priority in Ireland’s coastal adaptation response, alongside other approaches to coastal adaptation.”
The researchers also noted that the national Coastal Exposure Index can help the Government, local authorities and coastal communities identify areas that may require closer assessment and additional resources.
Senior Lecturer in Marine Geosciences at UCC Dr Aaron Lim said the research gives Ireland “a unique opportunity to be proactive rather than reactive”.
“For the first time, we can identify where exposure to coastal climate hazards is greatest and use that evidence to guide national strategy and targeted regional action.
“The decisions we make over the coming decade will shape how well our communities, infrastructure, businesses and cultural heritage can adapt to rising seas, coastal flooding and erosion.”