Interoperability: A conceptual framework to bridge the gap between multifunctional and multisystem urban flood management

Urban flood management is increasingly expected to be multifunctional to integrate with the existing functioning of cities. Locally, this led to the development of sustainable urban water drainage designs, while at larger scales, blue-green or water-sensitive cities are considered as examples for how cities should function. Upscaling local designs to city-scale flood resilience is not straightforward, however, due to the complexity of physical infrastructure and socio-economic interactions within urban systems and requires "system-of-systems" thinking. To this end, we introduce the concept "interoperability" to guide transition from local multifunctionality to city-scale multisystem flood management, through actively managing connections between infrastructure systems to convey, divert, and store flood water. While flood management is already based on these connections, interoperability is about explicitly emphasising them to explore and create opportunities to facilitate the integration of systems for flood management. The main research need arising from this conceptualisation is to determine how spatial data on infrastructure, environment, and social characteristics in urban areas can serve as a basis to identify opportunities and barriers for interoperability. By introducing interoperability and the research needs arising from it, a framework is created to facilitate and encourage practical thinking and discussion about system integration in urban flood management.