Expert perceptions regarding the effectiveness and feasibility of nature‐based solutions for climate change adaptation in a large Mediterranean Basin

Abstract Floods and droughts are becoming increasingly frequent and intense in the Mediterranean region. Nature‐based solutions (NBS) are being put forward as cost‐effective solutions for climate change adaptation to reduce the impacts of floods and droughts and provide multiple other benefits and ecosystem services. This fundamental change in adaptation to extreme climate events is supported by scarce empirical evidence and fragmented knowledge on NBS effectiveness and feasibility to mitigate increasingly prolonged and extreme droughts and floods, leading to limited uptake. Expert‐based approaches can help assemble the fragmented empirical evidence and identify implementation barriers and opportunities to inform policy and decision‐makers at an early stage in the selection of NBS. In this study, we conducted expert consultation to gather experts' perceptions on the most effective and feasible NBS to mitigate the adverse effects of floods and droughts in the large Mediterranean Segura River basin in southeast Spain. Our results show that, according to experts, reforestation of headwaters and NBS affecting river and floodplain morphology should be prioritized over solutions in agricultural land and urban areas. Conversely, NBS affecting river and floodplain morphology were perceived as least feasible to implement due to required land expropriations resulting in high economic costs, social rejection and low political support. Experts considered NBS as promising solutions to mitigate floods and droughts and complementary to grey infrastructures; however, they were more convinced about the effectiveness for mitigation of floods than for droughts. To overcome barriers and support NBS implementation, responsible governance of the territory, provision of training to policy makers and economic investment stood out as priority actions. Read the free Plain Language Summary for this article on the Journal blog.