Lu et al. (2025) A micro–macro coupled approach to assess urban road traffic flood risk at the city scale

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-10-18
• Authors: Xianfu Lu, Zongxue Xu, Yongkun Li, Xiaohong Hu, Pengyue Song, Qingli Shi
• DOI: 10.1016/j.jhydrol.2025.134435

Research Groups

• College of Water Science, Beijing Normal University
• Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology
• Beijing Water Science & Technology Institute

Short Summary

This study developed a micro-macro coupled dynamic risk assessment model, integrating hydrodynamic-hydrological, multi-agent, and system dynamics models, to evaluate urban road traffic flood risk and the effectiveness of mitigation strategies at the city scale. The model demonstrated that comprehensive mitigation measures significantly reduce dangerous vehicles and validate preemptive flood prevention strategies.

Objective

• To assess the indirect impacts of urban flooding on road traffic by developing a dynamic risk assessment model that integrates coupled hydrodynamic-hydrological, multi-agent system (MAS), and system dynamics (SDs) models, enabling multi-scale risk assessment of flood-vehicle interactions.

Study Configuration

• Spatial Scale: City scale, specifically a typical catchment area in Beijing's Qinghe River basin, including roads like Anningzhuang West Road, Anningzhuang East Road, Anningzhuang Middle Street, and Qinghe Middle Street.
• Temporal Scale: Simulation of 50-year recurrence rainfall scenarios, with observations at specific time points (e.g., T = 2.4 h, T = 2.5 h, T = 4 h, T = 7.5 h, T = 10.0 h).

Methodology and Data

• Models used: Coupled hydrodynamic-hydrological model, Multi-agent system (MAS), System dynamics (SDs) model. Models were developed on the NetLogo platform.
• Data sources: Simulated 50-year recurrence rainfall scenarios.

Main Results

• At the macroscopic scale, both MAS and SDs models showed a progressive decrease in safe vehicles as road flooding intensified. Under baseline conditions, safe vehicles stabilized at 198 agents (75.0 % of total) at T = 7.5 h and T = 10.0 h, with dangerous vehicles comprising 25.0 %. The models showed a high coefficient of determination (R² = 0.969).
• Emergency rescue interventions initially reduced the number of safe vehicles (MAS: 91.29 % at T = 2.5 h; SDs: 93.56 % at T = 2.4 h) before a recovery phase, with an inter-model R² of 0.775.
• Comprehensive risk mitigation measures maintained safe vehicle proportions between 99.0 % and 100 %, limiting dangerous vehicles to ≤1.0 %, validating preemptive flood prevention strategies.
• At the microscale, vehicles along Anningzhuang West Road, Anningzhuang East Road, Anningzhuang Middle Street, and Qinghe Middle Street transitioned into a hazardous state at T = 4 h under baseline conditions. Targeted rescue and risk avoidance strategies significantly reduced or eliminated dangerous vehicles at critical flood-prone locations.

Contributions

• Development of a novel micro-macro coupled dynamic risk assessment model integrating hydrodynamic-hydrological, multi-agent system (MAS), and system dynamics (SDs) models for urban road traffic flood risk.
• Proposal of operational protocols and communication mechanisms for three agent categories (disaster-pregnant environment, hazard-inducing, vulnerability-bearing) to enable multi-scale risk assessment.
• Validation of the effectiveness of preemptive flood prevention strategies through comprehensive risk mitigation measures at both micro and macro scales.

Funding

Not specified in the provided text.

Citation

@article{Lu2025micromacro,
  author = {Lu, Xianfu and Xu, Zongxue and Li, Yongkun and Hu, Xiaohong and Song, Pengyue and Shi, Qingli},
  title = {A micro–macro coupled approach to assess urban road traffic flood risk at the city scale},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134435},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134435}
}