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An integrated coastal vulnerability approach to small islands: The Azores case

Ng, Kiat, Borges, Paulo, Phillips, Michael Robert, Medeiros, António, Calado, Helena
The Science of the total environment 2019 v.690 pp. 1218-1227
Anthropocene epoch, climate, coasts, decision support systems, ecosystems, geographic information systems, islands, land use, planning, risk assessment, storms, Azores
Coastal development in small islands needs adapting to climate and ecosystem changes in the Anthropocene era. Understanding variability of coastal vulnerability along the entire coastline informs coastal planning and management at an island-wide scale as some coastal stretches are more appropriate for big-scale development, while others require additional coastal protection and/or ecosystem conservation. To date, few researches focused on developing macro-scale coastal vulnerability index at an island or archipelagic-scale. This paper fills a knowledge gap by developing an integrated coastal vulnerability index (ICVI) for nine small islands in the Azores archipelago. Considering that degree of vulnerability varies according to human-environment traits of each coastal stretch, this paper characterises integrated coastal vulnerability according to three broad attributes, i.e. exposure to external stressors, biophysical features and socioeconomic characteristics. Using field work, semi-quantitative analysis and GIS, ICVI is a simple and relatively quick approach that provides a broad overview of coastal vulnerability in small island context. A set of six accessible and representative parameters was employed as indicators for this vulnerability assessment, i.e. type of cliff; type of beach; coastal defences; exposure to swell/storm waves; outcrop flooded and land-use. The entire coastline of each island was divided into segments according to their geomorphic compartments and subsequently assigned with a relative ICVI value. Each segment was ranked into five classes ranging from very low to very high based on its relative degree of vulnerability. While majority of the coasts are of moderate relative vulnerability in the Azores, vulnerability varies broadly along the coast between low, moderate and high. The ICVI approach serves as a useful decision support tool to facilitate effective planning and management for the Azores small islands and the methodology has the flexibility of being scaled deep by adding more indicators where necessary and available or scaled out to other small islands.