Mapping disappearance: spatial analysis of vulnerable coastal destinations

Abstract

Many coastal regions around the world face increasing risks from both natural and anthropogenic drivers, including climate change, rising sea levels, and rapid, unauthorized urbanization. This study presents an integrated geospatial approach to evaluate the coastal vulnerability of Visakhapatnam and Uppada Village, both located in coastal Andhra Pradesh, India. These areas are exposed to multiple natural hazards and disasters but lack comprehensive multi-temporal analysis. This research uniquely integrates remote sensing and GIS with a multi-parameter coastal vulnerability assessment and extensive field validation, representing a comprehensive 35-year evaluation (1990–2024) of these critical coastal zones. To assess overall coastal vulnerability, five physical parameters were considered: Shoreline change, coastal slope, land use/land cover, relative sea level, and mean tidal range. The results were further validated through field visits. The findings indicate significant shoreline erosion at both locations, with Uppada Village identified as a highly vulnerable coastal zone experiencing ongoing and rapid erosion. In Visakhapatnam, erosion rates have reached a maximum of −13.1 m/year, alongside accretion rates of up to 21.1 m/year in certain areas, resulting in a net average coastline retreat of 64 m between 1990 and 2024. In contrast, Uppada Village has experienced consistent erosion along its coastline, with rates reaching −3.95 m/year and no notable accretion, resulting in an average loss of 90 m over the study period. Uppada Village lacks natural protective features and exhibits a uniformly high level of vulnerability due to wave action and sea-level rise. In Visakhapatnam, both anthropogenic and natural factors have contributed to coastal vulnerability. These findings underscore the urgent need for government and multi-stakeholder intervention to conserve these sensitive coastal areas. Potential measures include the implementation of both soft and hard coastal engineering solutions, as well as nature-based approaches such as mangrove restoration and seagrass development. If no action is taken, and current erosion rates of −3.95 m/year persist, significant portions of Uppada’s coastline face a high risk of severe degradation within the next two to three decades. This study provides essential baseline data and actionable recommendations for policymakers, coastal managers, and stakeholders to support the development of evidence-based adaptation strategies for these increasingly vulnerable coastal regions.