BLUE-Coast PHYSICAL PROCESSES AND COASTAL RECOVERY The complexity of
sediment dynamics processes in the water column, at the seabed, and at
the water-land interface are not well understood. Important questions
include: i) which processes dictate cross-shore and/or alongshore
sediment fluxes? ii) Which processes govern the recovery period of
coastal systems? iii) How sensible are coastal areas to changes in
external forcing? The
goal of BLUEcoast is to answer these and many other questions by
using field data and numerical models. (NERC Highlight topics, at
University of Liverpool, National Oceanographic center, Cambridge
University, Plymouth University, British Geological Survey, HR
Wallingford, University of Southempton, University of St Andrews,
Birbeck Univerisity of London, Cardiff University). . |
| IMPACT OF HURRICANE SANDY ON THE SALT MARSHES OF CHINCOTEGUE BAY, VIRGINIA, AND BARNEGAT BAY In
October 2012
Hurricane Sandy impacted the United States Atlantic Coast
with its >68 billion of dollars of damage. We are working with the
United States Geological Survey to understand salt marsh resilience to
violent storms and hurricanes, and to develop new numerical models and routines for
wetlands erosion and sediment transport processes. We
are using the numerical model COAWST (ROMS+SWAN+WRF) to model
wetlands behavior under different wave climate and storms conditions.
(Cooperative agreement with US Geological Survey, Woods Hole Science
Center, Boston University, University of Liverpool; with Sergio
Fagherazzi (BU), and Neil Kamal Ganju (USGS)). |
|

TIDAL HYDRODYNAMIC AND EXTREME WATER LEVELS IN HYPERTIDAL ESTUARIES
Predicting extreme water levels within estuaries is essential for
coastal management strategies. The interaction between storm surges and
tides is nonlinear and influences water levels. Huge spatial variability
can occur between tidal gauges along estuaries, and even small changes
in elevation can cause huge differences in inundation extent. We
are studying the tide-surge interaction in the Severn Estuary by using
the ocean model POLCOMS and Delft3D. (with Jennifer Brown (NOC),
Charlotte Lyddon (NOC, UoL), Andy Plater). |
| SALT MARSH
Salt marshes
are coastal
wetlands. They are ecosystem based flood defenses, and among the
most productive ecosystems on earth. In recent years, there has been a
flurry of restoration projects aimed at mitigating the impact of
coastal storms using salt marshes and vegetated surfaces. However, salt
marsh losses have been documented worldwide because of land use changes,
wave erosion and sea level rise. We are studying salt marsh evolution and erosion by wind waves using cellular
automata models, and 3D hydrodynamic and sediment transport models like COAWST (ROMS+SWAN+WRF), and Delft 3D. |
|
SIMPLIFIED COMPLEXITY MODELS
Cellular
automata ad simplified complexity models use simple stochastic rules to
reproduce systems behavior. Simplified complexity models are useful in
geomorphology as they can help extracting universal features of the
systems, and model emergent properties. Above
a simple invasion percolation model for salt marsh erosion under low
and
high wave energy conditions (white is the sea; black is the eroding
marsh). Low wave energy and slowly eroding salt marshes correspond
to
rough marsh boundary profiles (right plot, higher fractal
dimension). High wave energy and rapidly eroding salt marshes
correspond to smooth marsh boundaries (left plot, low fractal
dimension). |
| HYDRODINAMIC & SEDIMENT TRANSPORT MODELS
Hydrodynamic and sediment transport models solve
the Navier-Stokes equations, and the advection diffusion equation to
simulate hydrodynamic and sediment transport processes. These
models can be also used to simulate the morphological evolution of
coastal environments. I
have been using the numerical model Delft3D, and COAWST (ROMS+SWAN+WRF)
to model the behavior of estuaries and bays, and to simulate their
morphological evolution. I have been also using the same models to
investigate the efficiency of different coastal protection
schemes. |
|
HYDRODYNMIC FIELD MEASUREMENTS
Acoustic instruments like ADCP (acoustic Doppler current profiler) transmit
and receive sound signals. The traveling time and frequency shift of
the echo gives an estimate for water velocity along the acoustic
path. I have been
deploying acoustic instrumentation, and analyzed the resulting data to
investigate the interaction between riverine discharge and tidal
hydrodynamic in Apalachicola Bay, Florida. |
| RIVER DELTAS AND MOUTH BARS
Mouth bars are the building units of river deltas.
The hydrodynamic, morphology and
stratigraphy of mouth bars can be affected by tides and river discharge regimes. For instance, even small tides can
strongly impact mouth bars formation and evolution. I
used the model Delft3D, as well as analytical formulations
for turbulent jet and sediment transport to study mouth bars
evolution and create analytical facies models for these morphological
units. |
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