Integrated Implementation and Validation of the ICARIA Risk Assessment Framework and Decision Support System (DSS) Applied in the Southern Aegean Region

The ICARIA Horizon Europe risk-assessment framework and web-based Decision Support System (DSS) were applied in the Southern Aegean Region (Greece) to quantify single- and multi-hazard climate risks (wildfire, heatwave, extreme wind) and to assess adaptation under historical and future climates (SSP1-2.6, SSP5-8.5). The study integrates high-resolution hazard layers (5 km Fire Weather Index, downscaled temperature extremes), satellite-derived land surface temperature (30 m LST for building exposure), asset-level exposure and vulnerability, and probabilistic event-tree-based multi-hazard modelling, and was tested with stakeholders in Rhodes and Syros. Results show increases in wildfire and ecological multi-hazard risk: ecological high-risk (categories 4–5) areas expand by ~10–15%, and economic high-risk zones by ~5–8%. On Rhodes, very high fire-weather days (FWI > 70) rise under SSP5–8.5, and the central mountains shift into the highest ecological risk (category 5). A multi-hazard indicator (FWI > 80, Tmax > 30 °C, wind > 10.8 m/s) identifies persistent future hotspots. The 2023 Rhodes wildfire (~17,600 acres burned; ~€1.29 M electricity, ~€400 k water damage, ~2500 livestock and ~60,000 olive trees lost; ~19,000 evacuees) supports model projections. Adaptation substantially reduces risk. Vegetation substitution (e.g., Ceratonia siliqua, low-flammability stands) cuts category-5 ecological areas by ~30–32% and high-risk economic areas by ~20% (single hazard) and ~28–34% (multi-hazard). On Syros, retrofitting 1980–2010 buildings reduces top-risk classes (4–5) by ~25–35% and lowers thermal-stress exposure. Stakeholder trials found the DSS user-friendly and useful for comparing business-as-usual versus adaptation scenarios and for strategic planning, while highlighting needs for broader hazard coverage and continued support.