Identifying Risk Components Using a Sewer-Road Integrated Urban Stormwater Model

Disasters caused by heavy rainfalls are of growing concern to researchers and government officials. While many studies have provided details of rainstorm-induced risks and efficient strategies for stormwater management, there is still a lack of attention to how the interactions between urban sewer systems and road networks during precipitation events affect sewer system performance and road inundation. To fill this gap, we have developed an integrated model that combines hydraulic characteristics and the topological structure of a sewer-road network system to explore the behaviour of these two interdependent systems and identify risk components during precipitation events. We apply the model to a watershed during different return periods of precipitation events in Cincinnati, Ohio, USA. The results reveal that the behaviour of some inconspicuous pipes has a significant impact on the sewer-road network system, resulting in a significant decrease in the system performance. Moreover, the interactions between road and sewer networks create multiple microstructures of connected components, which leads to different risks of interdependent systems and road inundations. The modelling results provide target areas for mitigation projects to reduce rainstorm-induced risks.