loading page

Development and application of a continental scale compound flood modeling system in a complex coastal flood plains
  • +10
  • Henok Kefelegn,
  • Hassan Mashriqui,
  • Js Allen,
  • Jason Ducker,
  • Ryan Grout,
  • Richard Gibbs,
  • Julio Zyserman,
  • Saeed Moghimi,
  • Yuji Funakoshi,
  • Ali Abdolali,
  • Andre Van der Westhuysen,
  • Trey Flowers,
  • Edward Clark
Henok Kefelegn
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States

Corresponding Author:hmyr12@yahoo.com

Author Profile
Hassan Mashriqui
National Oceanic and Atmospheric Administration (NOAA), Office of Water Prediction, National Weather Service (NWS), Silver Spring, United States
Author Profile
Js Allen
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile
Jason Ducker
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile
Ryan Grout
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile
Richard Gibbs
University of Alabama, Tuscaloosa, AL, United States
Author Profile
Julio Zyserman
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile
Saeed Moghimi
NOAA National Ocean Service, Silver Spring, MD, United States
Author Profile
Yuji Funakoshi
NOAA National Ocean Service, Silver Spring, MD, United States
Author Profile
Ali Abdolali
NOAA Environmental Modeling Center, College Park, MD, United States
Author Profile
Andre Van der Westhuysen
NOAA Environmental Modeling Center, College Park, MD, United States
Author Profile
Trey Flowers
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile
Edward Clark
NOAA Office of Water Prediction, National Water Center, Tuscaloosa, AL, United States
Author Profile

Abstract

We present a high-resolution continental-scale compound flood modeling system. It aims to quantify inland flooding resulting from the composite effects of riverine discharge and surface runoff and storm surge, in the inland-coastal zone during significant riverine and coastal storm events. This is achieved by coupling three continental models: the National Water Model (NWM) for the hydrology component, the Advanced Circulation Ocean Model for the coastal storm surge component, and the WAVEWATCH III model for the surface wave component with a detailed inland-coastal inundation model as the mediator between coastal and inland hydrology module. The inundation model, Delft3D FM, D-Flow Flexible Mesh (D-Flow FM), uses a high quality 2D unstructured grid with high-resolution (~100 m) near coastal features and lower-resolution in other areas to resolve the geometry of the study area. The coastal features are collected from NWM streamlines, National Hydrography Dataset, US medium shorelines and bathymetric features from the United States Army Corps of Engineers . The D-Flow FM model is forced by time-varying water levels and riverine discharges applied at its offshore and inland boundaries, respectively, by spatially- and time-varying wind and pressure fields and incorporates the contributions of surface and subsurface runoff to the total discharge in rivers, channels and streams. We conducted model validations for the following four major flooding events across the US coast: Hurricanes Ike (2008), Sandy (2012), Irma (2017), and Florence (2018). The results highlight the importance of including composite effects of compound flooding to accurately predict water levels during combined river flooding and extreme storm surge events.