An assessment of the vulnerability of the coastline of County Cork using a geoinformatics driven approach
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Date
2026-04-16
Authors
Chalençon, Emma
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University College Cork
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Abstract
Coastal regions are increasingly exposed to climate change, sea-level rise, and intensifying human pressures, creating an urgent need for robust and decision-relevant assessments of vulnerability. However, existing approaches are often constrained by fragmented evidence bases and conceptual limitations. A review of the international literature highlights several critical gaps: the scarcity of consistent long-term shoreline change data in many regions, the predominance of Coastal Vulnerability Indices (CVIs) that focus narrowly on physical hazards and geomorphology, limited integration of social, economic, and environmental systems, and a lack of empirical validation linking index-based assessments to observed coastal behaviour. These shortcomings hinder the development of comprehensive, policy-relevant vulnerability assessments.
This thesis addresses these gaps through a geoinformatics-driven framework for assessing coastal vulnerability along the coastline of County Cork, Ireland. The approach integrates multi-decadal shoreline change analysis, sustainability-oriented vulnerability modelling, and field-based monitoring across multiple spatial and temporal scales.
To address the lack of baseline physical data, long-term shoreline change rates were derived from historical aerial photography using an automated vegetation-line extraction method designed for spectrally limited Red-Green-Blue imagery. The workflow employs colour vegetation indices, particularly the Normalised Green-Blue Difference Index (NGBDI), combined with iterative threshold optimisation and LiDAR-based constraints to produce spatially consistent shoreline positions with quantified uncertainties of approximately 0.6-1.2 m. This enables robust multi-decadal change rates and provides a scalable alternative to manual digitisation for data-limited coastlines.
Recognising the limitations of conventional CVIs, a Sustainable Coastal Vulnerability Index (SCVI) was developed to capture the multidimensional nature of vulnerability. Grounded in systems thinking and sustainability principles, the SCVI integrates five interrelated dimensions, coastal hazards, physical, socio-cultural, economic, and environmental susceptibility, representing both exposure and the capacity of coupled human-environment systems to respond to change. The index was implemented for the County Cork coastline within a Geographic Information System using 23 spatial indicators mapped at 50m resolution. Indicator weights were derived using the Analytic Hierarchy Process, and a multi-stage sensitivity analysis assessed the robustness of results to methodological choices. The analysis revealed pronounced spatial heterogeneity, with vulnerability hotspots emerging where hazardous processes, susceptible landforms, concentrated assets, and high-value ecosystems coincide, demonstrating that vulnerability is shaped by the interaction of human and environmental systems, not solely by physical hazard intensity.
To ground modelled vulnerability and remotely sensed proxies in empirical observations, a monitoring programme was established at five representative sandy beaches, Pilmore, Garretstown, Garrylucas, Inchydoney, and Owenahincha. Repeated Uncrewed Aerial Vehicle (UAV) surveys, Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS) profiles, and targeted post-storm campaigns generated high-resolution digital surface models and elevation-change analyses, revealing spatially compartmentalised and temporally variable morphodynamic responses driven primarily by sediment redistribution rather than uniform shoreline retreat. Comparisons between multi-decadal vegetation-line trends, short-term morphological change, and index-based vulnerability illustrate how interpretations of coastal change depend strongly on the proxy, scale, and observation period considered.
Collectively, this thesis demonstrates that coastal vulnerability cannot be adequately characterised through single indicators, scales, or disciplinary perspectives. By integrating historical imagery analysis, sustainability-framed spatial modelling, and field-based monitoring, it delivers a transparent and transferable framework for evidence-based coastal management. The geoinformatics-driven approach provides tools to screen, prioritise, and communicate vulnerability at regional scale while explicitly acknowledging uncertainty, scale dependency, and the limitations of proxy-based assessments. The resulting datasets, methodologies, and decision-support products support climate adaptation planning for County Cork and offer a model applicable to other data-limited coastal regions.
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Keywords
Coastal monitoring , Shoreline change , Coastal vulnerability , Sustainable management , Coastal hazards , Transdisciplinary , Coastal management , Erosion
Citation
Chalençon, E. 2026. An assessment of the vulnerability of the coastline of County Cork using a geoinformatics driven approach. PhD Thesis, University College Cork.