Fig. 1: Illustration of key compound flooding concept and associated roadway costs.
From: Local damages drive network-wide costs in compound flood-prone coastal city
a Cross-section of a coastal region illustrating roads, residential areas, green spaces, an open coastline, a river cutting through the area, and an underground stormwater drainage system comprising pipes, manholes, and outfalls. The outfalls connect to both the river and the ocean, highlighting the intricate interplay of natural and built environments. Black arrows within the stormwater drainage indicate gravitational water flow direction, while a red arrow represents the backwater effect caused by reverse flow from the river and tides. Areas submerged due to extreme precipitation depict pluvial flooding, regions near the coast experiencing high tides illustrate coastal flooding, and river floodplain areas with high water levels show fluvial flooding. Zones where these processes converge are marked as experiencing compound flooding. b Conceptual illustration of vehicle movement showing normal traffic behavior prior to a flood event. c Depicts flood-induced roadway costs, including direct road damage and indirect damage from traffic congestion, resulting in time loss and increased vehicular emissions due to prolonged congestion. d Illustrates the types of flood-related road damage and their respective measurement units.
