LOSING THE EDGE - GAINING GROUND. MAPPING CLIMATE CHANGE AND COASTAL CLIFF LOSS AT HERITAGE SITES
Channel: European Association of Archaeologists
Date: 2020-12-31

The remote western coastlines of Wales are home to many hundreds of protected heritage sites, among them some of the most iconic prehistoric coastal promontory forts in western Britain. These cliff-top or coastal prehistoric settlements are battered by waves and storms and scoured by salt-spray. Increasing storminess, the threat of sea level rise and higher wave-overtopping through climate change increases their vulnerability to erosion and collapse, and the loss of archaeological stratigraphy without record. Accurate geomatic data, including modern mapping or LiDAR better than 1m resolution, is vital to monitoring long term change yet in remote western Wales this can be entirely lacking. The 5 year EU-funded CHERISH project is looking to reinstate precision data for long term monitoring of its Welsh coastal study sites. New remote sensing data, including 25cm airborne LiDAR for six principal Welsh islands coupled with aerial and drone-based photogrammetry of coastal cliff sites and promontories, allows accurate baselines for long-term monitoring to be established. On the ground dGPS surveys are used to fix eroding coast edges. A century of change can be mapped against recent datasets using georeferenced nineteenth-century mapping and orthorectified historic aerial photographs. CHERISH will leave a legacy of securely archived high resolution coastal datasets allowing the impacts of future erosion and climate change to be more precisely monitored and understood.


Author(s): Driver, Toby (Royal Commission; CHERISH Project)