Hazard mapping over wastewater treatment plant as point critical infrastructures using a multi-hazard, multi-scale approach

Nowadays, natural extreme events are increasing in frequency and intensity due to climate change. These phenomena negatively impact critical infrastructures, such as wastewater treatment plants (WWTPs), resulting in a loss of their functionality and the generation of hazards to the environment and the population. It is important to identify and assess the hazards to which critical infrastructure is subject due to natural extreme events. Based on these considerations, through this work, the vulnerability of the territory and WWTPs of Sicily (south of Italy) was evaluated by using Geographic Information Systems (GIS) tools and a multi-hazards approach. The multi-hazard approach allowed determining the combined effect on the territory of different hazards (seismic, hydraulic, geomorphological and coastal), starting from the assessment of individual hazards and considering their possible simultaneous action. To this end, a multi-hazard spatial index was defined and subsequently mapped. This index represents an essential starting point for later defining a regional multi-hazard index map. Additionally, potential environmental and health consequences related to the occurrence of extreme events near wastewater treatment plants were assessed. This approach provides valuable guidance to local and regional authorities, aiding in the prevention, management, and mitigation of multi-hazard natural disasters.