Hydrodynamic Assessment of Natural and Nature-based Features for
Escatawpa River and Grand Bay in the Northern Gulf of Mexico
Abstract
This presentation showcases a hydrodynamic assessment of natural and
nature-based features (NNBFs) for the Pascagoula River, the Escatawpa
River and Grand Bay, located along the Mississippi coast of the northern
Gulf of Mexico. Two separate NNBF projects are being considered to: (1)
restore the historical footprint (ca. 1848) of Grand Batture Island for
coastal protection purposes; and (2) reconnect the hydraulics between
the Escatawpa River and Grand Bay for ecosystem services purposes. The
intended coastal protection benefits of the first project include
buffering agency to wave attack and attenuation of storm surge with the
restored island. The intended ecosystem services benefits of the second
project include replenishment of sediments to the salt marsh via
increased hydroperiod (duration of tidal inundation) and availability
for sediment accumulation. Astronomic tide and storm surge simulations
are performed with the advanced circulation (ADCIRC) plus simulating
waves nearshore (+SWAN) model to evaluate the hydrodynamic impact of the
NNBF projects (Image). The simulated hydrodynamics are assessed firstly
in terms of storm surge and waves for the open coast with and without
the restoration of Grand Batture Island (Passeri et al., 2015), and
secondly for tidal datums and inundation extent for the salt marsh with
and without the hydraulic reconnection of the Escatawpa River with Grand
Bay (Alizad et al., 2018). A key outcome from the analysis is the
interconnectedness of the hydrodynamics within the system, where the
implementation of the NNBFs results in local and non-local impacts. The
numerical modeling approach with high-resolution feature definition at a
system-wide scale affords such methodical evaluation of NNBFs for
ecosystem restoration.