Water Shortage Risk (WSR) map is a tool to establish priorities to take actions in the management of Urban Water Supply Systems (UWSS). This work presents a methodology combining elements of Multi-Criteria Decision Analysis (MCDA) and Geographic Information Systems (GIS) to assess urban water shortage levels. The study case is Campina Grande, a Brazilian city which represents other cities of semi-arid with similar conditions, such as dry climate, water rationing periods and a mixed-income population. The WSR approach uses seven criteria, including hydraulic, socio-economic, and infrastructure and a set of weighted functions. The method used for weight allocation is the Analytic Hierarchy Process (AHP). Results show the WSR map as a dynamic tool, once it can be complemented with utility and operational data. The WSR map, combined with control variables, can be a planning instrument for automation and operational control and also for highlighting the inequalities in water supply services.

Hazards act upon vulnerability and exposure to create disaster risk. Despite the growth of disaster risk assessments, the number of approaches that develop vulnerability and exposure studies is still small when compared with hazard modelling. In fact, limited studies have considered the relationship between vulnerability and exposure variables and how this can change future management actions on a local scale. This paper addresses this gap by proposing an integrated framework with a combination of social and environmental sciences to map hazard-specific vulnerability and exposure in urban areas. Subjective (e.g. Participatory Approach) and objective methods (e.g. Shannon Entropy and Fuzzy Theory) were integrated into a pixel-by-pixel framework for enhancing the flooding management in Campina Grande, Brazil. The results express the spatial distribution of flood vulnerability and exposure and assess key issues for flood management in different vulnerability categories. Challenges for the integration of socio-environmental approaches in water resources studies are discussed.

Nature-based solutions (NBS) support the provision of multiple benefits for the environment and society. First idealised in 2008, NBS are recommended by worldwide reports and guidelines as strategies to protect, sustainably manage and restore ecosystems. However, their operationalisation is still in the early stages, especially in developing countries, and only a few studies consider their full potential. This article contributes to this context by developing an integrated framework, with spatial and participatory tools, for analysing flood risk mitigation in Brazil. The approach enables a deep understanding of the societal challenges and vulnerabilities of the area (i.e., NEEDS) for subsequently planning the appropriate NBS (i.e., ACTIONS), with the participation of 255 stakeholders of Campina Grande municipality. Results show mappings of flood-prone areas, in which approximately 52% of the flooded areas will see an increase in the future. Hotspots (i.e., hazard, vulnerability, and exposure) are shown and discussed with four application cases. Finally, multiple benefits of seven NBS alternatives are analysed in 53 scenarios of application, in which the higher rates of reductions are found to combined alternatives. The discussion emphasizes the importance of spatially assessing the ‘needs’ and ‘multiple benefits’ of NBS, including reducing vulnerabilities and increment of resilience.

Since hazards act upon vulnerability and exposure to become disasters, the understanding of societal challenges is key for disaster risk reduction. This condition is even more critical when more than one hazard is in place. Taking the case of flooding and water shortage, this study is built upon the premise that disasters are a social phenomenon; therefore, it is essential to comprehend the social context in which they occur. Particularly, this study aims to evaluate the similarities and differences in risk perception and the coping capacity of residents in the multiple-hazard context. For this, a place-based citizen science approach was developed in this study in Campina Grande, a semiarid region of Brazil, with the collaboration of 199 participants. Risk perception and coping capacity were analysed through the citizens’ participation, while combining subjective and objective methods. The results indicate that even though residents have experienced severe flooding and water shortages in the past, they still have low coping capacity. The findings highlight the need to combine a triad of societal challenges, namely information, trust, and incentives, to improve coping capacity in the future and increase resilience. This study underlines the need to understand multiple hazards according to social, spatial, and temporal scales in a socio-spatial perspective.

There are different perspectives of what constitutes disaster risk. Among the “hazards”‐tradition research, more focus is given to modelling hazards, and less effort is made to understand the vulnerabilities. Considering vulnerabilities as the inherent characteristics of the place that create the potential to harm, this paper highlights the importance of understanding the vulnerabilities of the place before defining actions for flood risk mitigation (FRM). In this sense, a participatory approach, the Project PLANEJEEE, was developed to understand the social and institutional vulnerabilities of FRM in Campina Grande, Brazil. Data was collected with the collaboration with 199 stakeholders through surveys, workshop and focus groups. The results reflect the analysis of risk perception and coping capacity of communities at risk (n = 172), and the institutional context with the involvement with policymakers and local specialists (n = 27). Although results confirm that individuals faced severe flood risk cases previously, they still need resources for increasing their coping capacity and their own risk protection. Institutional vulnerabilities are shown with the contrast between challenges and actions for FRM. Findings show that multiple challenges in social and institutional contexts should be systematically addressed to propose actions to reduce flood risk vulnerability, and increase resilience.

In developing countries, the urbanisation process occurs with empirical urban management, a high increase of impermeable areas, and a lack of connection between water resource management and planning. In Brazil, concentrated rainfall and ineffective urban drainage systems add to this context and may impact the population with flash floods. Although sustainable drainage systems (SuDS) are widely used for flood mitigation, it is still not very well known how those strategies behave in semi-arid regions, where most of the time the weather is very dry. In Brazil, flood mitigation still mostly involves structural measures such as larger pipes or channels, with limited guidance for SuDS use due to the great resistance to change by citizens and managers. This study sought to analyse the efficacy of SuDS in Campina Grande, a semi-arid region of Brazil. A land-use and legislation-based methodology was developed with physical, climate, hydrological and governance data for three catchments and 312 sub-catchments in 30 applications and simulations. Simulations suggest that these strategies would be appropriate for semi-arid regions, with reductions in the flooded area, flooding volume, and impacts. This study is of relevance for cities with a similar climate to reach a sustainable level of urban drainage services, supporting the integration of urban planning and water resources management.