RETURN VTB River Flooding

The dataset represents hazard and impact scenarios for the two Virtual Test Beds (coastal and inland) developed within the RETURN project, considering both present hazard conditions and projections for the end of the century.

To estimate flood hydrographs at the base of hazard scenarios, under historical and far-future climate conditions, high-resolution Convection-Permitting Climate Models (CPM) were used, which provide more reliable sub-daily precipitation extremes compared to coarser-resolution regional climate models. The SMEV (Simplified Metastatistical Extreme Value) approach (Dallan et al., 2024a,b) was then applied to precipitation time series derived from CPM simulations allowing the estimation of intensity–duration–frequency (IDF) relationships under changing climate conditions. The design hyetographs obtained from the SMEV analysis were finally used as input to the hydrological model to simulate flood hydrographs (Norbiato et al., 2009) corresponding to 100 yr return period. The resultant flood inundation extend and features were derived using HEC-RAS software.

For each hazard scenario, the dataset includes:

• -        Digital Terrain Models (DTM) used for the simulations, provided in GeoTIFF raster format
• -        Output rasters representing maximum water depth and maximum flow velocity, provided in GeoTIFF raster format

The impact scenarios are assessed across three dimensions (Built Environment, Individual Well-being, and Public Services), according with the Hazards–Impacts matrix developed within the RETURN project (Molinari et al., under review). Specifically, the impact scenarios are organized into two subfolders (one for each VTB) and include impact estimation, in shapefile format, structured as follows:

• -        Built environment: damage to private commercial assets, damage to private industrial assets, damage to residential buildings, damage to roads.
• -        Individual well-being: affected people, direct physical damage, indirect physical damage.
• -        Public services: reduced access to education, reduced access to health services, reduced access to transport services.