CC BY 4.0Martini, TillTillMartiniBoigk, MaurizioMaurizioBoigkCatal, FarukFarukCatalDietze, SteffenSteffenDietzeGerold, MichaelMichaelGeroldLukau, EridyEridyLukauMonteforte, MichaelMichaelMonteforteNeuhäuser, StefanStefanNeuhäuserPeitzsch, SaschaSaschaPeitzschPhung, Windy FookWindy FookPhungPfennigschmidt, StefanStefanPfennigschmidtSimon, MaikMaikSimonVetter, JoannaJoannaVetterWinter, NilsNilsWinterAdams, GabrielGabrielAdamsFinger, JörgJörgFingerRosin, JuliaJuliaRosin2025-07-142025-07-142025https://doi.org/10.24406/publica-4877https://publica.fraunhofer.de/handle/publica/48950610.1007/s10669-025-10035-010.24406/publica-4877The increasing frequency and severity of significant risks to public safety posed by natural disasters or human-induced events have underscored a critical need for evaluating the vulnerability of urban regions with a focus on their essential infrastructures. This paper presents a novel methodology for the virtual representation of infrastructure vulnerabilities and functional impairments during hazard situations. Thereby, focus is on the mapping of interdependencies among critical infrastructure systems and the cascading effects that can arise from failures within these heterogeneous sectors by means of a digital twin representation. An integration of simulation models for urban infrastructure components, particularly in relation to the built environment and emergency response systems is introduced. Leveraging a modular co-simulation architecture, the framework facilitates the analysis of cascading effects across multiple infrastructure systems, such as water, electricity, gas, and telecommunications. As a proof-of-concept example, urban flooding due to heavy rainfall is considered to illustrate the framework’s capabilities in predicting system states and assessing structural impacts on critical infrastructures as well as consequential ramifications for emergency relief units. The findings contribute valuable insights, thereby advertising the utilization of the presented methodology in decision-making and training resources aiding the enhancement of the resilience of urban environments against both natural and intentional threats.enDigital Urban TwinSocio-technical systemsDistributed co-simulationCrisis managementjournal article