Tsunami preparedness risk assessment in Andalusian West Coast, Spain (2020-07-31)

Activation date: 2020-07-31

Event type: Flood

Activation reason:

The Spanish General Directorate of Civil Protection and Emergencies (CENEM) has triggered the Copernicus Emergency Management Service (CEMS) Risk and Recovery Mapping to develop tsunami risk analysis in the urban environments along 300 km of the Andalusian West Coast, totaling an area of about 6,780 km2. This activation supports civil protection preparedness activities in the area, and its results include information on tsunami hazard, exposure, and vulnerability of the buildings. The risk and recovery mapping products depict the reference datesets, model tsunami hazard via highly efficient numerical simulations (Tsunami-HySEA), and calculate the tsunami vulnerability returning a Relative Vulnerability Index for each building of the area of interest.Product 1 - General reference cartographyThe reference mapping displays the main territorial characteristics such as topographic, population, industry and transportation features, as well as points of interest within the AOI. It was specially focused on the elaboration of a complete building layer. Building polygons were extracted from the Cadastral dataset (MINHAP), updated with the use of PNOA aerial imagery; the resulting product is a geometric layer containing all the footprints of the buildings present in the area of interest, with information on characteristics of the buildings (such as building material, year of construction, shape, and orientation), useful to evaluate the vulnerability of the structures to the modelled tsunami wave (see below).Product 2 - Tsunami event modelThis product represents the tsunami hazard assessment based on a worst-case scenario framework. Three seismic meg-sources were initially selected based on expert advice and the available bibliography. The numerical simulation of these three events served to choose the most suitable seismic source for the simulation. The calculation was implemented using the Tsunami-HySEA model, a numerical code developed by the EDANYA group of the University of Malaga (UMA), which was directly involved in the activation, representing the state-of-the-art in tsunami modelling. For the entirety of the Andalusian West Coast, the model could calculate the tsunami wave height time series, the tsunami arrival times, the run-up of the inundation along the coastline, and the maximum height, maximum speed, and maximum flow in the inundated area.Product 3 - Tsunami vulnerability modelThe tsunami vulnerability of the buildings is based on the combination of the reference cartography, comprising detailed information on characteristics of the buildings, and the information on inundation height, output of the tsunami modelling. The method applied is the Papathoma Tsunami Vulnerability Assessment (PTVA-3), which combines the structural and water vulnerability of each building to express a relative vulnerability index (RVI) for each building of the area of interest.