Participatory approaches for planning nature-based solutions in flood vulnerable landscapes

In vulnerable areas, where floods are frequent, decision-making through participatory workshops has proved highly applicable and yielded positive results in integrated management issues. This paper examines Nature -Based Solutions (NBS) to provide flood risk mitigation and proactive adaptation options. The case study con-cerns the Kalloni river basin (Lesvos Island, Greece) which represents a highly flood-prone area. Participatory methods and community-based approaches according the methodology developed in Vulnerability and Capacity Assessment (VCA), are used to evaluate NBS options and determine their design and implementation frame-work. As part of this approach, a diverse group of local stakeholders, experts and decision-makers joined a series of interviews and workshops aimed at prioritizing NBS's proposed practices based on their sustainability at social, economic and environmental level. The small-scale mountainous dams, afforestation and planting mea-sures appeared to be the most acceptable alternatives. After the examination of the digital elevation model and the estimated water and sediment flow, the construction sites of five gabion and three wooden wall dams in river tributaries' bottlenecks were selected. For every selected site, the slope stability and suitable spillway, as well as the frontage and cross-section were calculated and finally their construction cost was estimated. This solution proved to be the most effective measure that provides environmental and social benefits. Ultimately, NBS strategies can drive the desired sustainable change through a combination of solutions for the wider basin resulting from a complex participatory and modeling approach, strongly depended on stakeholder's active contribution and government intervention.

Automated summary

In vulnerable areas with frequent floods, participatory workshops have been proven to be highly effective in decision-making and integrated management. This paper examines Nature-Based Solutions (NBS) for flood risk mitigation and proactive adaptation in the Kalloni river basin in Greece, a highly flood-prone area. Using participatory methods and community-based approaches, stakeholders prioritized and evaluated NBS options based on sustainability at social, economic, and environmental levels. Small-scale mountainous dams, afforestation, and planting measures were found to be the most acceptable alternatives. Construction sites for gabion and wooden wall dams were selected based on examination of elevation models and estimated water and sediment flow. This study shows that NBS strategies, dependent on stakeholder involvement and government intervention, can drive sustainable change.