Nature Based Solutions for Water Management: A Critical Review of 21 Case Studies from around the World

Nature-based solutions (NBS) are interventions for sustainable management and development of natural resources. It protects the ecosystem and biodiversity and overcomes any existing social barrier. Applications of nature-based solutions have been more effective than conventional technical interventions in water management. This research aims to understand the existing knowledge based on the applications of NBS in different countries and situations for water crisis management through a critical analysis of 21 case studies. The case studies are divided into four main categories: major objective, global distribution, major NBS application, and success (failure) stories. A total of seven factors (water crisis and flood/flood-livelihood management, groundwater replenishment, environmental degradation, and slope instability prevention, payments for ecosystem services (PES), land degradation prevention, agro-ecology transformation, and disaster management of watershed areas and wetlands) were observed by analyzing the main objectives of these case studies. Among them, most studies are related to water crises, floods, food livelihood management, and payments for ecosystem services (PES). A worldwide analysis of study areas shows that the use of NBS interventions in water management has been more widely applied in African river watersheds than in the other three continents (Asia, North America, and South America). About 81% of cases are successful while NBS interventions have been made. Advanced ecosystem services obtained through the use of NBS will directly help to achieve the UN Sustainable Development Goals.