Barriers and enablers for the implementation of large-scale Nature-based Solutions for flood mitigation in the Po Valley, Italy

Abstract

Nature-based Solutions (NBS) represent holistic, cost-effective approaches that address complex challenges while yielding multiple co-benefits, thereby being an alternative to or complementing traditional "grey" solutions. Large-scale NBS have proven effective in mitigating floods, particularly in flood-prone countries like the Netherlands (NL). Moreover, these measures not only provide long-term flood mitigation but also enhance habitat, ecosystems, and human well-being. However, in the Po Valley (PV), a crucial socio-economic area in Northern Italy susceptible to catastrophic floods, large-scale implementation and research on NBS for flood mitigation are still lacking. The PV relies on an extensive embankment system to manage floods, but this method is considered insufficient to meet the future challenges posed by climate change, land use, and urbanization, which are projected to increase the frequency of catastrophic floods. Given the similarities between the NL and the PV in terms of landscape, socio-economic development, and flood-related challenges, a comparative analysis of the ex-ante and ex-post barriers and enablers to large-scale NBS uptake between these regions could provide lessons for the PV to promote NBS implementation to enhance flood protection. A mixed-method approach based on both qualitative and quantitative research was adopted, including literature reviews, spatial modelling, and interviews with experts. First, the impacts and causes of floods in the PV were examined to provide background information on the magnitude of the issue. Second, ex-ante and ex-post barriers and enablers to NBS adoption in the PV and the NL respectively were investigated. Then, the comparison between barriers and enablers allowed for the identification of lessons for the PV to take up from the NL experience. Lastly, a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis was conducted to highlight potential opportunities and threats associated with NBS implementation or non-implementation in the PV. In general, findings reveal that the PV faces more and greater barriers than the NL, while enablers are often hindered by short-term and small-scale actions. Lessons from the NL thus highlight the importance of long-term, integrated, and participative strategies for policymakers and stakeholders to foster large-scale NBS implementation for flood mitigation in the PV. By doing so, the PV can address future flood-related challenges by providing large-scale and long-term flood protection and achieving co-benefits deriving from NBS implementation.