River flood risk assessment for the Chinese road network

Abstract

Frequent floods substantially impact transportation infrastructure. This study assesses river flood risk to Chinese road networks by expected annual damage (EAD) and expected annual network efficiency loss (EAEL). The results show that the EAD of Chinese roads under river floods ranges from 2.04 to 3.42 billion USD, and the EAEL of 366 cities ranges from 0 to 31.0‰. The EAD high-risk cities are concentrated in areas of frequent flooding with high road network densities, while EAEL high-risk cities have relatively sparse roads and a high percentage of failed nodes and edges under river floods. For different income groups, the average EAD is the highest in the high income group, while EAD relative to the GDP and EAEL are the highest in the low and lower middle income groups, respectively, placing greater financial pressure on local governments. Our study provides an integrated view for assessing and managing road flood risk.