Estimation of the Coastal Vulnerability Index Using Multi-Criteria Decision Making: The Coastal Social–Ecological System of Rachgoun, Western Algeria

Abstract

This research deals with spatial vulnerability in the coastal area of Rachgoun (Algeria), on the southern shore of the Mediterranean Sea. Over the past two decades, the coastal area of Rachgoun has been suffering from a large amount of pressure due to accelerated socioeconomic development, urbanization, tourism, fishing, and agriculture. The main objective of this study is to visualize the coastal vulnerability of Rachgoun using multi-criteria decision making (MCDM). A multidisciplinary approach that integrates geological, physical, and socioeconomic vulnerability was adopted. The selected parameters for the study include lithology, elevation, slope, shoreline change, significant wave height, population density, tourist density, land use/land cover (LULC), road network density, proximity to coast, distance from river, people’s awareness, and designated conservation areas and cultural heritage. Data from AlSat-2 Satellite imagery, aerial photography, topographic maps, and field surveys were processed. Spatial modeling was conducted through the MCDM approach and geographic information systems (GIS) to develop two sub-indices: the natural vulnerability index (CVIN) and the socioeconomic vulnerability index (CVIS). The combination of the two sub-indices allowed us to deduce the integrated coastal vulnerability index (ICVI). The outcomes present a coastal vulnerability map with a spatial resolution of 10 m of the identified problematic area. This map can guide decision-makers in implementing an effective integrated coastal zone management (ICZM) strategy.