System dynamics for water management in coastal cities under multi-risk scenarios

In the context of global warming, extreme weather events are rising in frequency and severity. Urban communities prosperity heavily depend on the balance of environmental and socio-technical systems to access to fundamental resources and services, making them more susceptible to the impacts of climate change. Coastal cities, in particular, are characterized by a high degree of vulnerability to climate variations, potentially leading to critical impacts if resilient and sustainable water management strategies and measures are not in place. To assess the significance of territorial adaptation and mitigation measures in a dynamic and holistic approach, the use of System Dynamics tools aims to study the effects and interactions of various sectors, examining the risks associated with flood management in coastal cities. This approach incorporates multidisciplinary, multi-scalar, and multi-operational dimensions, supporting stakeholders in identifying potential measures for building resilient pathways. By identifying interactions within the various interconnected sub-systems that influence the dynamic behaviour of the overall system, stock and flow models enable complex systems to be analysed through interdependent components that influence each other over time. It can be used to support decision-makers in getting insights about the potential effects of different policies and strategies. The model presented is a conceptual framework able to represent the impact of compound coastal flood (combination of pluvial, river and coastal flood) on sectors (transport, energy, landuse, etc.) and explores adaptation and mitigation measures (Nature Based, architectural and engineering solutions) to contrast coastal risks using dynamic tools and methods for assessing their relevance in urban coastal areas. The different types of water storage and flows/processes have been identified, namely: coastal flow, surface water, river/ponds, soil water, groundwater table, city drainage system. These are used to simulate different scenarios and study the interlinks among technical solutions, urban features, and coastal flood water management. The presentation explores SD thinking and tools for dialogue and decision-making on complex and interdisciplinary issues linked to Climate Change Adaptation and Disaster Risk Reduction actions. The quantitative developed stock and flow model contributes to study the climate impacts on coastal cities under a cross-sectorial approach.