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Abstract Compound flooding, characterized by the co‐occurrence of multiple flood mechanisms, is a major threat to coastlines across the globe. Tropical cyclones (TCs) are responsible for many compound floods due to their storm surge and intense rainfall. Previous efforts to quantify compound flood hazard have typically adopted statistical approaches that may be unable to fully capture spatio‐temporal dynamics between rainfall‐runoff and storm surge, which ultimately impact total water levels. In contrast, we pose a physics‐driven approach that utilizes a large set of realistic TC events and a simplified physics‐based rainfall model and simulates each event within a hydrodynamic model framework. We apply our approach to investigate TC flooding in the Cape Fear River, NC. We find TC approach angle, forward speed, and intensity are relevant for compound flood potential, but rainfall rate and time lag between the centroid of rainfall and peak storm tide are the strongest predictors of compounding magnitude. Neglecting rainfall underestimates 100‐year flood depths across 28% of the floodplain, and taking the maximum of each hazard modeled separately still underestimates 16% of the floodplain. We find the main stem of the river is surge‐dominated, upstream portions of small streams and pluvial areas are rainfall dominated, but midstream portions of streams are compounding zones, and areas close to the coastline are surge dominated for lower return periods but compounding zones for high return periods (100 years). Our method links joint rainfall‐surge occurrence to actual flood impacts and demonstrates how compound flooding is distributed across coastal catchments.
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Rainfall Runoff and Flood Simulations for Hurricane Impacts on Woonasquatucket River
Integrated hydrological and hydrodynamic modeling study has been conducted to investigate hurricane impact on Woonasquatucket River, Rhode Island, USA. Model simulation was conducted for the case study of 2010 storm event. The hydrological model simulates the runoff from the heavy rainstorm, while the river hydrodynamic model simulates the flood waves affected by the interactions of upstream rainfall runoff and downstream storm surge. Results indicate that the river floods was dominant by rainfall runoff in upper river reaches, but dominant by storm surge in the lower river area near the estuary
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- Award ID(s):
- 1832068
- PAR ID:
- 10188004
- Date Published:
- Journal Name:
- International journal of structural and civil engineering research
- Volume:
- 9
- Issue:
- 3
- ISSN:
- 2319-6009
- Page Range / eLocation ID:
- pp. 239-244
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.18178/ijscer.9.3.239-244
