Flood risk assessment of potential land-pollution hotspots in the area of “Basso Valdarno” (Central Italy)

Among the risks related to floods caused by extreme climatic events, the spread of pollutants stored in land-pollution hotspots is an aspect which has been rarely examined with a rational risk-based approach. In this contribution, an attempt to estimate pollution risks related to possible floods of land-pollution hotspots was carried out. The assessment was performed on a geographical basis, using geo-referenced data available on the databases of land management Institutions, Authorities and Agencies. The list of considered land-pollution hotspots included landfills and other waste handling facilities (temporary storage, treatment and recycling sites), urban wastewater treatment plants, liquid waste treatment facilities as well as the list of National and Regional Relevance Contaminated Sites in wait of remediation. The assessment was performed by cross-linking the geo-referenced data of potential land-pollution hotspots with flood hazard maps. We derived maps of land-pollution risks based on simple parameters such as type of stored pollutants, type of facility, capacity, size of the area, land use, and other geographical and geological characteristics. The analysis was applied to the lower stretch of the Arno river basin in Tuscany (central Italy), from the town of Pontedera to the mouth into the Tyrrhenian sea near the town of Pisa, where the main river course is mostly surrounded by levees.