Coastal vulnerability assessment in complex geological and changing climate conditions

Summary

Abstract

The paper provides an overview of the impact of coastal processes on coastal zones in the Kvarner area (channel part of the northeastern Adriatic Sea), recent instability phenomena, and the effects of climate change on their occurrence. The study focused on the coastal area near Stara Baška on the southwestern coast of Krk Island. The delicate geodynamic balance, combined with a complex geological structure and active coastal processes, makes this area particularly prone to erosion and landslides induced by wave action and sea-level rise. Rockfalls and rock slumps in these areas represent a natural hazard while also serving as a source of beach-forming sediment. The complexity of the geological structure required an adaptation of the methodology for assessing coastal vulnerability. A novel coastal vulnerability analysis was carried out using existing data complemented by detailed field investigations. The Coastal Vulnerability Index was calculated at 5-m intervals along approximately 2 km of coastline, representing a newly developed high-resolution methodology enabled by precise 3D datasets obtained from UAV and LiDAR surveys. Geological structure, coastal slope, beach width, significant wave height, and land use were taken into account. The results of the new high-resolution vulnerability assessment were validated through field investigations and comparison with orthophoto maps, confirming the reliability of the proposed approach and highlighting the importance of detailed spatial data for accurate coastal vulnerability evaluation.