Flood Hazard Assessment in Two Eastern Mediterranean Catchments Using a Multi-Indicator Approach

Floods triggered by intense precipitation represent one of the most significant natural hazards affecting Mediterranean regions, where complex terrain, rapid hydrological response and increasing urbanization can amplify flood impacts. This study presents a flood hazard assessment for two representative Eastern Mediterranean catchments: the Koiliaris River Basin in Crete-Greece and the Pediaios River Basin in wider Nicosia region in Cyprus. A composite Flood Hazard Index was developed by integrating three indicators representing key drivers of flood generation: the Topographic Wetness In-dex describing terrain-driven water accumulation, the Curve Number representing runoff potential, and the R20 precipitation frequency index. Spatial datasets including EU-DEM elevation data, CORINE land cover, European soil databases and precipita-tion information from the Copernicus CERRA reanalysis were used to derive the indi-cators. Each indicator was classified using the Natural Breaks method and combined through a weighted multi-criteria approach based on the Analytic Hierarchy Process. The resulting maps identify high-susceptibility areas mainly along river corridors and low-lying zones with high runoff and accumulation potential. Higher hazard levels occur in downstream areas of Koiliaris and urbanized zones of the Pediaios basin, par-ticularly around Nicosia. Historical flood events were also analyzed to validate the index and examine links between rainfall intensity and impact severity.