Multiple criteria-based assessments of Nature-Based Solutions for flood management: a review

Increased flooding frequency and intensity threaten vulnerable populations’ lives and livelihoods worldwide. Fitting into the preparedness and mitigation phases of the Disaster Risk Management framework used by humanitarian and conservation organisations, Nature-Based Solutions (NBS) have been advanced as effective alternatives to traditional grey infrastructures in order to mitigate flooding impacts. By reproducing natural processes, NBS have shown to provide multiple environmental, social, and economic benefits in addition to their technical performance in mitigating floods. However, a framework to systematically assess these co-benefits is not readily available, which is an obstacle to the effective implementation of NBS on a larger scale. This paper develops such a framework using a Systematic Literature Review (SLR) based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) method. The framework includes a set of descriptors to characterize and analyse NBS consistently. These include:Type of NBS; Type of protection area (coastal, urban, rural, mountainous, riverine); Provided environmental/technical/social/economic benefits; Location of applicability; Scale of implementation; Inclusion of stakeholders’ preferences for NBS implementation. The  SLR is shaped using a combination of scholarly literature (via Web of Science) and grey literature from reputable organizations in the NBS domain and beyond, including the WWF Nature-based Solutions Accelerator, the United Nations Office for Disaster Reduction, the Disaster Risk Management Knowledge Centre, and the Geneva Environment Network. The resulting framework can support decision-making and facilitates the deployment of sustainable infrastructure. The Red Cross Red Crescent Movement and WWF will test the framework in a case study in the Zambezi river basin in Zambia.