Researchers have created the Global Coastal Heritage (Glo-CoH) dataset, the first comprehensive digital map of UNESCO World Heritage sites located along coastlines that are less than 20 meters above sea level.
The project, led by scientists from the University of East Anglia (UEA), Durham University, and University of Cape Town, was developed in response to growing concerns that climate change and coastal development are putting many historic and natural treasures at risk.
“This dataset will provide an important tool for scientists, conservationists, and policymakers,” said Prof Robert Nicholls, from the Tyndall Centre for Climate Change Research at UEA and the University of Southampton.
“It can be used to better understand how environmental and climate-related threats could affect coastal heritage sites, helping authorities plan protection measures and make informed decisions at local, regional, and global levels.
“As sea levels continue to rise and storms cause increasingly powerful surges and waves to batter coastlines, we hope this new resource will play a vital role in protecting some of the world’s most valuable cultural and natural landmarks for future generations.”
Until now, experts have struggled to accurately assess which heritage sites are most vulnerable because detailed digital boundary maps were often unavailable. This has made it difficult to model the potential impacts of hazards such as storm surges, flooding, and erosion.
The new dataset addresses this by providing precise digital boundaries for every UNESCO World Heritage property of ‘Outstanding Universal Value’ situated in low-lying coastal areas around the world. The dataset is based on the UNESCO list of World Heritage Sites as of 2023 but the team will be updating it to 2026 by the end of this year.
In total, the database includes 1,250 individual heritage sites, spanning cultural landmarks, sites of natural importance which contain unique ecosystems, geodiversity and rare species, and mixed heritage locations, classified as being of both natural and cultural significance.
These range from the Sydney Opera House in Australia, the coastal sections of the Great Wall of China, the Moai of Rapa Nui, and much of St Petersburg in Russia. Together the sites cover more than 235 million hectares across the globe.
Prof Joanne Clarke, who led the team of digitisers while at UEA, and more recently at Durham University, said: “One of our key aims was to create a comprehensive, up-to-date catalogue of spatial boundaries for coastal World Heritage properties, giving heritage managers a reliable tool to assess, plan, and respond to future threats, whether they’re looking at environmental, climatic, economic, infrastructural, or societal aspects.
“By making the dataset publicly available and in an accessible format, we are enabling heritage professionals, researchers, and scientists around the world to use this information to undertake their own analysis and modelling to meet the needs of their own projects and applications.”
To create the maps, the international team of researchers used published site plans alongside Google Earth satellite imagery to identify and carefully trace the boundaries of each heritage site.
The team then carried out a rigorous quality-checking process, assessing factors such as the quality of source materials, the accuracy of site identification, and the precision of the digitized boundaries.
The results showed the mapping was highly reliable, with 92 percent of sites achieving scores that indicated the highest levels of digitization accuracy.
Dr. Nicholas Simpson, from the University of Cape Town, said: “This dataset represents years of painstaking, detailed work translating UNESCO’s own site records and satellite imagery into boundaries that are accurate enough to support real risk assessment.
“It’s the kind of unglamorous groundwork that almost never gets funded. Datasets like this don’t get built without people willing to do the detailed, repetitive work that never makes it into a headline.
“The research group are already using Glo-CoH to power two further global studies: a global sea-level risk assessment of coastal heritage sites, and an assessment of climate risk to biodiversity at these sites, focused on thermal exposure of reef-building coral species and mangroves.”
The work was funded by Irish Aid, the British Academy, and UK Natural Environment Research Council.
‘Mapping the global distribution of coastal World Heritage Sites: Glo-CoH, a new Global Coastal Heritage dataset’, is published in Scientific Data on July 24.
