Modeling the resilience of urban mobility when exposed to the COVID-19 pandemic: A qualitative system dynamics approach.

In December 2019, coronavirus disease (COVID-19) was detected in Wuhan, China. Due to the rapid spread of the disease, containment measures were adopted, which caused unprecedent shifts in individual mobility. Although some studies explored the impacts of the COVID-19 pandemic on travel patterns and resilience of transport systems based on different analysis techniques, there is a lack of studies addressing the impacts of the pandemic on the sustainability and resilience of urban mobility systems using in-depth and holistic methods, such as system dynamics. This research aims to characterize the dynamics present in urban mobility systems when exposed to pandemics and analyze the changes needed for systems to increase their resilience to pandemics using qualitative system dynamics modeling. The framework comprises the characterization of cause-and-effect relationships and the creation of systems' causal loop diagrams (CLD) in their basic state of functionality, when affected by pandemics, and still operating owing to its resilience. Our findings indicated that the CLD of a resilient system is driven by strategic preparedness and response plans, as well as research and development, which balance the spread of the pandemic and increase support on technological strengths and the activities performed from home.

Application of Systems Thinking to the assessment of an institutional development project of river restoration at a campus university in Southern Brazil.

Rapid urban growth and high population density have become a problem for urban water resources, especially in developing countries. In general, the pollution of rivers and degradation of ecosystems are the result of both management failures and lack of sewage treatment. River restoration appears as a solution to improve this scenario, but it is common for there to be an absence of a systemic vision in these projects. Thus, this work analysed one of these projects as an initial approach to create coherent (qualitative) shared perspectives on the same problem. This project was developed in a Brazilian university territory in response to a Public Civil Action. Rivers within the university surroundings are degraded due to sewage disposal and wastewater pollution from external and internal sources within the university, but the programme actions contemplate only interventions within the perimeter of the university while excluding the other parts of its watershed. We analyse this problem under a Systems Thinking approach by using causal loop diagrams, being clear that ecosystems cannot be reduced to territorial limits only. The systemic map shows many actions that contribute to the water quality degradation, with emphasis on illegal dumping of wastewater (sewage) and land use change in the upstream areas prior to the university. Point measures are palliative and do not guarantee the quality of river water. Regulation of impervious surfaces and correct disposal of wastewater can improve the current panorama, but greater integration between stakeholders and other key actors is required.