Dynamic impact assessment of urban floods on the compound spatial network of buildings-roads-emergency service facilities

Yawen Zang; Jing Huang; Huimin Wang

doi:10.1016/j.scitotenv.2024.172007

Dynamic impact assessment of urban floods on the compound spatial network of buildings-roads-emergency service facilities

Sci Total Environ. 2024 May 20:926:172007. doi: 10.1016/j.scitotenv.2024.172007. Epub 2024 Mar 27.

Authors

Yawen Zang¹, Jing Huang², Huimin Wang³

Affiliations

¹ Institute of Management Science, Hohai University, Nanjing 211100, China.
² Institute of Management Science, Hohai University, Nanjing 211100, China; The National Key Laboratory of Water Disaster Prevention, Nanjing 210098, China.
³ Institute of Management Science, Hohai University, Nanjing 211100, China; College of Management and Economy, Tianjin University, Tianjin 300072, China; The National Key Laboratory of Water Disaster Prevention, Nanjing 210098, China. Electronic address: hmwang@hhu.edu.cn.

PMID: 38552969
DOI: 10.1016/j.scitotenv.2024.172007

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 dynamic impacts of time-varying 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, building vulnerability, 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 the compound spatial network were analyzed. The results show that: (1) Flooded building comprehensive risk analysis reveals that floods have a significant impact on residential and commercial land use, and high-risk flood areas are mainly concentrated in the central region of study area. (2) The road network has a collapse threshold, 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 comprehensive risk and emergency service accessibility, presenting complex dynamic changes over time. 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.

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