Potential socio-economic impacts of ground movements in the coastal municipalities of Spain: Insights from the supra-regional implementation of the European Ground Motion Service

This study assesses the vulnerability of the Spanish coastline—a major global tourism destination—to ground movements, providing for the first time initial estimates of the potential socio-economic impact of this phenomenon in this highly strategic territory. Using Interferometric Synthetic Aperture Radar (InSAR) data from the European Ground Motion Service (EGMS), an InSAR-based service developed under the Copernicus initiative, we evaluated the coastline's exposure to natural and human-induced ground movements, and their potential impacts on the road network, buildings, and population. Utilizing a suite of post-processing tools including ADAfinder, we identified a series of Active Deformation Areas (ADAs) and classified them based on their prevailing movement (vertical or horizontal) and displacement rate. As a result, a dataset consisting of 9010 ADAs spread across Spain's 805 coastal municipalities was generated, with 1916 ADAs affecting roadways and 2596 affecting buildings. Most ADAs exhibited predominant vertical movement, primarily associated with land subsidence, although ADAs exhibiting horizontal movement, mainly linked to landslides, were also significant. The majority of ADAs showed moderate to low displacement rates (<25 mm/yr). We calculated a potential economic impact (in 2021€ values) of €19,428.4 million, with €1716.4 million attributed to the road network and €17,712.0 million to buildings. Additionally, we identified a total of 134,236 people potentially vulnerable to these processes. Results highlight both a higher exposure of Spain's Mediterranean coast compared to the Atlantic coast and a higher exposure of the Canary archipelago compared to the Balearic Islands—with the most vulnerable regions being Andalusia and Region of Murcia. This research underscores the potential of the EGMS for conducting both preliminary population exposure analyses and preventive risk assessments to mitigate road and building damage.