Author(s): Yawen Zang; Jing Huang; Huimin Wang

Linked Author(s):

Keywords: Dynamic assessment; Compound spatial network; Building flood risk; Road risk; Emergency service accessibility; Complex impacts

Abstract: There are complex interactions among urban spatial elements in rainstorm scenarios. Road interruptions may cause isolation between partially submerged buildings and emergency service facilities, thereby affecting the recovery capability of flooded buildings and the accessibility of emergency service facilities. This study constructed a compound spatial network of urban buildings-roads-emergency service facilities, and analyzed the complex impacts of dynamic floods on building risk, road risk, and emergency service accessibility. Firstly, a refined flood risk assessment at the building scale was carried out in combination with flood inundation, flood loss, population, vulnerable areas, underground buildings, and life facilities. Secondly, betweenness centrality indicator in complex networks was used to calculate road traffic capacity and collapse threshold, and the accessibility of emergency service facilities is calculated based on road traffic capacity. Finally, the interaction and feedback relationships between building flood risk and emergency service accessibility were analyzed. The results show that: (1) building flood risk analysis reveals that floods have a significant impact on residential and commercial losses, and high-risk flood areas are mainly concentrated in the central region of study area. (2) The road network has a collapse threshold when t=3h, and the fluctuating state of emergency service accessibility is significantly influenced by road traffic capacity. (3) Roads act as "bridges" connecting buildings and emergency service facilities, leading to the redistribution of building flood risk and emergency service accessibility, presenting complex dynamic changes. Additionally, submerged roads also affect the accessibility of emergency service facilities around flooded buildings, reducing the recovery capacity of flooded buildings, and exhibiting significant heterogeneity characteristics. Future research should consider the complex impacts of floods on urban elements in order to better manage dynamic flood risk.

DOI: https://doi.org/10.3850/iahr-hic2483430201-494

Year: 2024