The urban drainage system plays an important role in the urban infrastructure resilience discussion. Its functional failures can trigger cascading effects on other urban systems and critical infrastructures. The main aim of this work is to investigate and quantify urban flood resilience, offering an integrated methodological approach. In this process, the flooding consequences were quantified by hydrodynamic simulations, using a case study in an exploratory research method. A set of indicators was proposed to map the cascading effects generated by floods and the consequent quantification of urban flooding resilience. Two simulation scenarios were proposed to validate the methodological assessment framework proposed in this work. The first scenario represented the current flooding situation and showed the negative effects on the city systems resulting from disordered urban growth. The second scenario considered the improvement of the drainage behavior, considering a sustainable urban drainage approach supported by the concept of blue-green infrastructure integrated with the urban open spaces system. A comprehensive flood resilience assessment over time was conducted by analyzing the evolution of the System Integrity Index on both scenarios. The results showed that water dynamics play an important role in ordering land use and that preserving water spaces can efficiently respond to urban developing threats, dealing with floods in an earlier development moment, proving the importance of the drainage system as a preliminary structuring driver for supporting a sustainable urban planning, ordered according to environmental constraints defined by water dynamics.

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.

In peripheral countries, the lack of adequate urban planning associated with natural dynamics intensifies the existing vulnerabilities of the environment, causing physical and material losses. Therefore, this research aims to discuss the potential use of Environmental Protection Areas as a tool to drive urban growth with a low-impact development, helping to mitigate urban floods and bringing nature into the city landscape. The municipality of Maricá, located in the metropolitan region of Rio de Janeiro, Brazil, is taken as a case study. The method proposed to drive the regional environmental planning and management can be described as a three-stage method coupled with the adapted SWOT Matrix, following: the diagnosis, the prognosis, and the action plan. This process points to the definition of a Hydrological Interest Area that would allow not only the restoration of local vegetation and a better interaction of the population with the watercourses, but also the recovery of areas that have been gradually impacted by the urban expansion. The method presented in this research allows its application in different urban contexts, once it has the objective of recognizing the strengths, weaknesses, opportunities, and threats to allow the elaboration of sustainable actions and guidelines.

Accelerated urbanization and frequent flooding in contemporary cities have contributed to the devaluation of rivers within urban landscapes, resulting in a diminished relationship between residents and these waterways. Although there has been a notable increase in frameworks designed to enhance stakeholder engagement in flood risk management, these primarily target decision-makers, with limited focus on processes that ensure community participation in Blue–Green Infrastructure (BGI) initiatives. This paper seeks to address this gap by proposing a conceptual framework for assessing public perceptions of BGI in urban watersheds, particularly in areas facing socioeconomic vulnerabilities. The framework was applied through an online survey directed at inhabitants and experts associated with the Acari River Watershed, Rio de Janeiro, Brazil. The survey comprises five sections aimed at gathering respondent profiles, exploring their interactions with the case study, and eliciting their perceptions of BGI alternatives, supported by graphic representations. BGI alternatives were evaluated based on four principles: usability, reliability, feasibility, and acceptance. The findings indicate that while certain strategies were perceived as reliable, concerns regarding pollution and trust were significant, especially in densely populated areas. This framework is recommended for use in other urban contexts to facilitate effective community engagement in sustainable planning processes, especially in developing countries.

No Brasil, a discussão acerca da interação entre o manejo sustentável das águas pluviais e o planejamento urbano tem sido gradualmente difundida em planos diretores municipais, como resposta aos desafios associados às mudanças climáticas, como as cheias urbanas. Nesse sentido, o objetivo desta pesquisa consiste na realização de uma análise crítica de uma amostra de planos diretores, com o intuito de identificar de que forma contemplam as Soluções Baseadas na Natureza. Para tanto, serão analisados os planos diretores das capitais do Sudeste do Brasil: Rio de Janeiro, São Paulo, Belo Horizonte e Vitória, com o apoio de três perguntas norteadoras e de uma pontuação que traduz uma percepção quantitativa que classifica essa articulação. Notou-se que os planos diretores mais recentes apresentam objetivos e diretrizes mais claras quanto à proteção dos elementos naturais e à adoção de práticas de mitigação e armazenamento de águas pluviais. Enquanto isso, os planos mais antigos, embora contenham princípios e técnicas compatíveis, apresentam menor interação com o conceito. Diante desse panorama, evidencia-se a possibilidade de que planos diretores futuros sejam adaptados de forma a promover maior articulação das Soluções Baseadas na Natureza com um espectro mais amplo de políticas setoriais, contribuindo para um planejamento mais sustentável.