Modeling Compound Flooding from Hurricane Florence Using ADCIRC

Hurricane Florence (2018) and several other recent hurricane events illustrate the enhanced impacts of the co-occurrence of storm-driven surge and extreme (record-setting) precipitation and resulting river flows on the coastal zone. If the riverine and coastal water levels co-occur in both space and time, the resulting compound flooding can greatly increase the inundation extents, damage, and effects on coastal resources and populations well beyond the impacts of the individual flooding source components. These events have thus motivated new research and applications into optimal approaches to more accurately simulate, and eventually predict, their impacts. This presentation describes comprehensive hindcasts of Hurricane Florence using the ADCIRC model that include detailed reanalysis and advanced parametric hurricane winds, inland river discharges from both USGS gauges and the NOAA National Water Model (NWM). Results indicate varying significance of compound flooding depending on the size of the catchment - river - estuarine system.