Refining Broad-Scale Vulnerability Assessment of Coastal Archaeological Resources, Lough Foyle, Northern Ireland

ABSTRACT

Increasing evidence indicates that ongoing and future climate change impacts, such as enhanced coastal erosion driven by intensified storms and sea-level rise, will be destructive or problematic for coastal archaeological heritage. Approaches to this problem range from broad-scale GIS-based vulnerability assessments to site-scale monitoring and survey. In all cases, the approach chosen should be based on the best-available data on the local historic environment and pattern of coastal change. Therefore, this paper will demonstrate how such data can be successively acquired and enhanced using an integrated approach that builds on and refines a previously conducted broad-scale vulnerability assessment. This approach was adopted in the study region (Northern Ireland) owing to a lack of coherent and up-to-date information on shoreline change. This approach incorporated the GIS-based Digital Shoreline Analysis System (DSAS) to quantify and analyze local shoreline change. DSAS is a software extension for ESRI ArcGIS which allows calculation of rate-of-change statistics using past shorelines identified from georeferenced historic maps and vertical aerial imagery. Additionally, a field survey was conducted to assess the condition of recorded sites, and identify unrecorded ones. Results revealed a more complex pattern of shoreline change in the study area (Magilligan Foreland, Lough Foyle) than previously anticipated, with zones of significant erosion interspersed with areas of stability or advance. Fifty-one new sites ranging from the prehistoric period to the Second World War were also identified. The new information was used to develop a priority classification based on site significance, condition and risk level which improved significantly on the uniform classification of the original broad-scale assessment.

Keywords:

• coastal erosion
• cultural resource management
• sea-level rise
• climate change
• coastal vulnerability

ACKNOWLEDGEMENTS

All research presented here was supported by the Historic Environment Division, Department for Communities (formerly the Northern Ireland Environment Agency: Historic Environment Division); thanks in particular to Rhonda Robinson, Claire Foley, and Rory McNeary. Thanks also to Sandra Henry for assistance with the field survey and Brian McNaught for information on the unpublished assemblage of pottery sherds. All mapping data and aerial orthophotos were provided by Land and Property Services for research purposes under the Northern Ireland Mapping Agreement; this Intellectual Property is Crown Copyright and is reproduced with the permission of Land and Property Services under Delegated Authority from the Controller of Her Majesty's Stationery Office, © Crown Copyright and database right (2017). Finally, thanks to two anonymous reviewers whose comments improved the original draft.

SUPPLEMENTAL

Supplemental tables and figures for this article are available at the publisher's website at https://doi.org/10.1080/15564894.2018.1435592.