Household flood risk mitigation is an important component of Integrated Flood Risk Management. Voluntary household decisions about whether or not to structurally mitigate or insure can directly and indirectly influence vulnerability to the flooding of a community. Serious games can augment existing data collection methods in the flood risk context by operating in the space in between stated and revealed preference, through observing decisions as opposed to asking abstract hypothetical questions, while allowing for complete control over experimental conditions. We look to answer the question of which individual and contextual factors contribute to the decision to mitigate against floods. We gather household decision-making data using a serious game role-play experiment named the Decision Game. Participants spent about 20 minutes making decisions about where to live and how to distribute limited income, given geographical information, including flood risk, about the city. We use a generalized linear mixed modelling approach to analyze the data. Among other findings, we see that experiencing an in-game flood had a strong positive effect, compared to a much weaker effect of a participant having experienced a real-life flood; our key observation is that incentivizing flood risk mitigation should be done quickly following a flood event. We find that real-life low-income individuals were no less likely to implement in-game mitigation measures than their higher-income counterparts, suggesting that subsidies to address an income barrier may be an effective method of encouraging low-income household mitigation. We apply the model to a case study of Calgary, Alberta finding that the insurance market could maintain cross-subsidization after a flood, making insuring higher risk areas more feasible. Moreover, we find that Calgarian policymakers should be encouraged to limit subsidy coverage to high-risk areas to avoid inefficient use of funds in low-risk areas which were projected to have the clear majority of program uptake. / Thesis / Master of Science (MSc) / We develop a research tool to help understand what drives people to protect themselves against flooding. This tool is a computer-based role-playing game experiment in which people take on the role of a homeowner tasked with choosing where to live and how to distribute their income. We log the decisions that people make in the game and use statistical analysis to figure out which factors are important in driving the decisions to insure against floods and to invest in protective structural measures. We find that experiencing a flood in the game has the largest positive effect on these decisions. The results of the model are used to inform a case study where we investigate potential outcomes of policy decisions in Calgary, Alberta. The development of this research tool and the findings contributes to optimizing policies to improve flood risk management through household interventions.

Heavy precipitation events are expected to increase in the future, due to climate change. This predicted change will increase the risk of flooding, especially in urban areas. To mitigate these challenges and support a sustainable urban development, Nature-based solutions (NBS) can be used as a flood risk reduction measure. The NBS wetlands and constructed wetlands, composed of ponds, canals and ditches, are commonly used solutions which are multifunctional and primarily provides flood regulatory services, water quality improvements and increased biodiversity. To reach the full potential of NBS, the location and design is crucial. At present planning practise, a user friendly and time efficient tool to investigate suitable locations within a catchment is missing, where the concept of connectivity has arisen as a useful approach. In this study, the NBS concept and the potential of wetlands for flood risk mitigation have been investigated. In addition, the connectivity of two study case catchments has been analysed by using the Connectivity Index (IC index) by Cavalli et al. (2013). The aim has been to evaluate whether the IC index can be used to find suitable locations for NBS. Further, the study seeks to investigate how the IC index can be integrated into NBS planning practice in order to create useful information for the decisionmaking process. To validate the IC index result, a comparison has been performed with earlier flood events, two hydrological models, Multi criteria decision analysis and spatiotemporal soil parameters. From the obtained result and analysis, preliminary solutions have been proposed for two case studies in Sweden and Portugal. The result shows that IC index is promising as an, early stage, first assessment tool in NBS planning practice which can be used in order to allocate areas suitable for NBS. To find the most beneficial location and the site-specific design, a deeper investigation of the site-specific conditions is required. Moreover, a successful implementation is dependent on a close collaboration between different stakeholders and expertise. Finally, this study shows that realizing the potential of NBS wetlands is essential to create sustainable urban development and liveable and attractive cities.