Choosing Nature-based solutions - Development of a multi-criteria framework for selecting nature-based solutions in the urban context

Abstract

Nature-Based Solutions (NBS) are increasingly gaining popularity due to their multifaceted benefits addressing various environmental and societal challenges for cities. The pursuit of achieving sustainable urban water management and enhancing resilience and well-being has expanded the range of NBS applications considered useful. Currently, traditional sustainable urban drainage practices sit alongside urban vegetation, such as parks, street trees and green facades, to address specific urban challenges, all delivering different benefits and tradeoffs. This diversity of applicable NBS introduces a decision-making challenge: Choosing appropriate nature-based solutions for cities.

To address this challenge, this thesis developed a framework to assist decision-makers in selecting a set of potential suitable nature-based solutions for urban areas. The tool combines a screening method with a multi-criteria analysis that integrates public preferences, benefits, and tradeoffs of NBS based on ecosystem service variables. The new methodology has been demonstrated in the city of Tam Ky, Vietnam. The case study results showed successful integration of public preferences, benefits, and tradeoffs of NBS based on ecosystem service variables in the selection process. Combining this data into a method to visually present rank scores allowed to holistically evaluate the performances of different NBS relative to each other. This output can aid decision-makers and planners in gaining a more holistic understanding of the importance of local ecosystem services, enabling to align potential suitable NBS with public wishes and needs, and selecting a set of potential suitable measures accordingly.