Fan et al. (2026) Full-Process simulation and risk assessment framework for compound flooding in inland cities with high external inflow

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-01-29
• Authors: Chenchen Fan, Jingming Hou, D. Li, Yongping Yang, Gangfu Song, Tian Wang, Jiahao Lv, Xuan Li, Guangzhao Chen, Peiqi Zhang, Yanhong Wang, Bingxue Li, Xinxin Pan, PinPin Lu, Yuying Yang, Ruixue Zhang
• DOI: 10.1016/j.jhydrol.2026.135024

Research Groups

• State Key Laboratory of Water Engineering Ecology and Environment in Arid Area, Xi’an University of Technology, Xi’an, Shaanxi, China
• Shaanxi Provincial Water and Drought Prevention Center, Xi’an, Shaanxi, China
• North China University of Water Resources and Electric Power, Zhengzhou, China
• Power China Northwest Engn Corp Ltd, Xi’an, China
• China Academy of Urban Planning and Design, Beijing, China
• Weinan Housing and Urban-Rural Development Bureau, Weinan, China

Short Summary

This study developed a multi-module dynamic coupling framework for comprehensive modeling and dual-indicator risk assessment of compound urban flooding in inland cities with high external inflow, revealing that external inflow primarily amplifies hydrodynamic risk while river backwater predominantly increases inundation risk.

Objective

• To create a multi-module dynamic coupling framework for comprehensive modeling and risk assessment of compound urban flooding in inland cities with high external inflow, considering the combined effects of precipitation, external input, and river stage fluctuations, and to characterize the corresponding risk progression.

Study Configuration

• Spatial Scale: Weinan City, China (a representative inland city with high external inflow).
• Temporal Scale: Event-based simulations for specific rainfall return periods (e.g., P = 100-year, P = 30-year rainfall scenarios).

Methodology and Data

• Models used:
  • Multi-module dynamic coupling framework
  • Semi-distributed hydrological module
  • Two-dimensional (2D) surface hydrodynamic module
  • One-dimensional (1D) drainage network module
  • One-dimensional river hydrodynamic module
• Data sources:
  • Precipitation (rainfall scenarios)
  • External inflow
  • River stages

Main Results

• Concentrated external inflow substantially altered surface runoff evolution, enhancing flow convergence and rapid conveyance along major road networks.
• Elevated river stages restricted outlet discharge through backwater effects, weakening drainage capacity and prolonging surface inundation.
• The dual-indicator assessment revealed a structural mismatch and partial spatial overlap between inundation risk (characterized by maximum water depth) and hydrodynamic risk (characterized by depth–velocity product).
• Inundation under a P = 100-year rainfall scenario was comparable to that under a P = 30-year rainfall scenario with external inflow.
• External inflow primarily amplified hydrodynamic risk by 659.39%.
• River backwater predominantly increased inundation risk by 73.06%.

Contributions

• Developed a novel multi-module dynamic coupling framework for comprehensive modeling and risk assessment of compound urban flooding, integrating hydrological, surface, drainage network, and river hydrodynamic modules.
• Introduced a dual-indicator risk assessment framework utilizing maximum water depth and the depth–velocity product to characterize both inundation and hydrodynamic risk under compound forcing.
• Quantified the distinct impacts of external inflow and river backwater on different aspects of urban flood risk (hydrodynamic vs. inundation).
• Provided new insights for optimizing drainage systems and enhancing flood resilience in inland cities susceptible to compound flooding.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Fan2026FullProcess,
  author = {Fan, Chenchen and Hou, Jingming and Li, D. and Yang, Yongping and Song, Gangfu and Wang, Tian and Lv, Jiahao and Li, Xuan and Chen, Guangzhao and Zhang, Peiqi and Wang, Yanhong and Li, Bingxue and Pan, Xinxin and Lu, PinPin and Yang, Yuying and Zhang, Ruixue},
  title = {Full-Process simulation and risk assessment framework for compound flooding in inland cities with high external inflow},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.135024},
  url = {https://doi.org/10.1016/j.jhydrol.2026.135024}
}