Pre-Print: Compound Inundation Modeling of a 1-D Idealized Coastal Watershed Using
a Reduce-Physics Approach
Abstract
Low-gradient coastal watersheds are susceptible to flooding caused by
various flows such as rainfall-runoff, astronomical tides, storm surges,
and riverine flows. Compound flooding occurs when at least one coastal
flood driver occurs simultaneously or in close succession with a pluvial
and/or fluvial flood driver, such as during a tropical cyclone event.
This study presents a one-dimensional (1-D), reduced-order physics
compound inundation model tested over an idealized coastal watershed
transect under various forcing conditions (e.g., storm surge,
astronomical tides, and rainfall) that varied in magnitude, time, and
space. This study aims to evaluate each flooding mechanism and the
associated hydrodynamic responses to identify generalized coastal
transition zones and enhance the production of flood maps for varying
regions in a coastal watershed. Compound inundation levels are affected
by the magnitude and timing of each flooding mechanism. The desire is a
more holistic compound inundation model that can be a critical tool for
decision-makers, stakeholders, and authorities who provide evacuation
planning to save human lives and enhance resilience.