Kasaei et al. (2025) Compounding of 100-year coastal floods by rainfall in an urban environment

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Environmental Research Letters
• Year: 2025
• Date: 2025-12-09
• Authors: Shima Kasaei, Philip Orton, Thomas Wahl, David K. Ralston, John C. Warner
• DOI: 10.1088/1748-9326/ae2a55

Research Groups

Research institutions or departments specializing in coastal hydrology, urban flood modeling, and climate change impacts, likely within the New York City region or the United States.

Short Summary

This study investigates the combined impacts of coastal and pluvial flood drivers, challenging the assumption that rainfall has a negligible effect on 100-year coastal flood maps. It finds that pluvial drivers can significantly expand flood zones and occasionally deepen floods, particularly in topographic depressions.

Objective

• To investigate the impacts of combined coastal and pluvial flood drivers and evaluate the circumstances under which they exacerbate flood impacts.
• To evaluate the implicit hypothesis of official flood maps, which assumes that rainfall has a negligible impact on the flood depth and flooded area due to a 100-year coastal flood.

Study Configuration

• Spatial Scale: Jamaica Bay watershed, New York City, USA.
• Temporal Scale: Historical period for rainfall data and joint probability analysis (spanning multiple decades to capture extreme events); event-based scenarios for flood simulations.

Methodology and Data

• Models used: A custom-configured coastal system model designed to integrate coastal and pluvial flood drivers.
• Data sources: Realistic scenarios of rainfall data derived from historical tropical cyclones; historical data for joint probability analysis (likely observational records of rainfall and coastal water levels).

Main Results

• The pluvial driver compounds the coastal flood primarily through expansion of the flood zone.
• There is a 17% chance of rainfall increasing the flood area by 6% to 38%.
• There is a 5% chance of an increase in flood area ranging from 61% to 73%.
• Significant deepening of floods is rare.
• When flood deepening occurs, it is more common for convergent zones (topographic depressions) than for coastal landfills.

Contributions

• Provides quantitative assessment of the potential for pluvial drivers to exacerbate coastal flooding.
• Challenges the implicit assumption in official flood maps regarding the negligible impact of rainfall during 100-year coastal flood events.
• Offers critical insights for improving emergency management strategies, including evacuation plans, shelter arrangements, and preparedness measures.

Funding

Not specified in the abstract.

Citation

@article{Kasaei2025Compounding,
  author = {Kasaei, Shima and Orton, Philip and Wahl, Thomas and Ralston, David K. and Warner, John C.},
  title = {Compounding of 100-year coastal floods by rainfall in an urban environment},
  journal = {Environmental Research Letters},
  year = {2025},
  doi = {10.1088/1748-9326/ae2a55},
  url = {https://doi.org/10.1088/1748-9326/ae2a55}
}