Capturing cascading effects under urban flooding: A new framework in the lens of heterogeneity

•A network modeling framework suitable for various types of heterogeneous risk factors in urban floods has been proposed.•Simulation of the cascading effects of heterogeneous hazard-bearing bodies in the city from a functional availability perspective under continuous flood attack.•The heterogeneous hazard-bearing bodies are interdependent and networked, which causes flood damage to spread more quickly and widely.•The greater degree and more propagating hazard-bearing bodies are key factors influencing the spread of flood risk and the cascading failure of functionalities in urban areas.