Environmental impacts of a flood: an overlooked problem - Evidences from the 2023 Italian floods

The European “Floods” Directive requires river basin district authorities to identify flood prone areas and potential adverse consequences on built and natural environments. However, there are few examples of methods to assess flood impact to environment at the spatial scale of river basin districts. Moreover, the lack of data concerning the environmental impacts occurred during past floods constrains their identification as well as the definition of empirical vulnerability models.

This work examines the environmental impacts of the 2023 floods in Emilia-Romagna (Italy), through the collection, analysis and georeferencing of information available on newspaper and social media after the event. The analysis highlights that damage to natural ecosystems is often overlooked compared to direct economic losses. The floods caused significant harm, including the release of pollutants, destruction of natural habitats, and disruption of ecosystem services. The most affected areas were water resources, aquatic ecosystems, and terrestrial habitats, with primary effects such as pollution, submersion, and erosion. Specific damages included bathing bans due to water contamination, interruption of bird nesting, fish and bivalve deaths, and alterations in coastal ecosystems. The impacts were spatially concentrated in coastal areas and river deltas, with temporal variability. Some effects, like bathing bans, were resolved within 30-45 days, while others, such as nesting disruption and soil contamination, had longer-term consequences. Assessing these impacts remains challenging due to the lack of systematic monitoring and shared methodologies. Natural resilience dynamics and indirect effects, including health and economic consequences, are also poorly understood. We conclude that a greater interdisciplinary focus is needed to understand and integrate environmental impacts into flood risk management. Future research should address specific ecosystem vulnerabilities and develop metrics for assessing damage based on ecosystem services.

Reference: Arrighi, C. and Domeneghetti, A.: Brief communication: On the environmental impacts of the 2023 floods in Emilia-Romagna (Italy), Nat. Hazards Earth Syst. Sci., 24, 673–679, https://doi.org/10.5194/nhess-24-673-2024, 2024.

Acknowledgements: This study was carried out within the RETURN Extended Partnership and received funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005)