A new approach to the assessment of flooding and dampness hazards in cultural heritage, applied to the historic centre of Seville (Spain)

Abstract Flooding and dampness have caused considerable damage to historic towns and cities and have become more frequent in recent years. The aim of this paper is to analyse the hazards of flooding and dampness in historic cities to establish a methodology that prioritises preventive conservation actions and restorations. The case study concerns the historic centre of Seville (Spain) and parish churches built between the 13th and 18th centuries. Geographic information system (GIS) software has been used to assess hazards caused by flooding and dampness along with a Delphi consultation process surveying a multidisciplinary group of seven experts—archaeologists, geologists, chemists, architects, engineers and environmentalists—to gain a general overview of the hazards affecting each area of the city. Currently, the historic centre of Seville is at a very low risk of flooding due to the engineering works being undertaken to divert the river course. For flooding to occur, water levels would need to rise over 6 to 12 m along the different sections of the defensive walls; as a result, the historic centre has not been flooded since 1961, when these defences broke. However, there is a continual presence of dampness due to the proximity of the river, the presence of underground water and the permeability of the subsoil, resulting in continual damage to the lower sections of the monuments studied. Hence, hazard maps of flooding and dampness need to be dovetailed. This new approach provides tools for decision-makers in the current crisis, allowing them to prioritise strategies that will minimise damage in a town, as the urban unit where territorial policies could be applied.