The use of blue-Green infrastructure as a multifunctional approach to watersheds with socio-environmental vulnerability

This article investigates how to make the implementation of blue-green infrastructure (BGI) more attractive to solve urban problems in densely occupied watersheds that lack flood control and environmental quality protection infrastructure. Considering the obstacles related to implementing multifunctional solutions in developing countries, measuring its co-benefits (in addition to flood control) may influence greater public and political acceptance. Thus, the paper uses a multifunctional design approach using the urban open space system and combining the blue-green and gray infrastructure. A hydrodynamic model was used to support flood mapping. This approach also increases the land value and the environmental quality of the urban spaces. Two quantitative aspects support this evaluation. The first one represents the land value increase as a positive effect, while the second one assesses the environmental quality of the urban space using the Environmental Quality Assessment Index (EQAI). The results obtained from the urban and environmental evaluation proved that blue and green corridors could promote multiple co-benefits for consolidated urban areas. The increased environmental quality and land value were only possible due to the combined use of BGI and gray infrastructure since BGI can add benefits that the gray infrastructure is not capable of providing.