The USGS is assessing the physical condition of coastal wetlands and their response to external forces, using field observations and remote-sensing data. The U.S.
Zafer Defne, PhD
My research finds its form in providing answers to questions related to coasts and ocean, based on my knowledge of physical oceanography and experience in data sciences.
Dr. Zafer Defne received his PhD in Coastal and Ocean Engineering from Georgia Institute of Technology, with a minor in Information Technology Applications in Oceanography. His expertise includes computational fluid dynamics and data analysis. His work on numerical modeling of coastal ocean has been used to assess storm surge, residual circulation, sediment transport and water quality, as well as marine renewable energy. His recent research is on assessment of the physical state of coastal wetlands using geospatial data.
Google Scholar
Science and Products
Estuarine Processes, Hazards, and Ecosystems
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S. Geological...
Coastal Model Applications and Field Measurements- Field Measurements and Model Applications
Several components of this project are applications to evaluate the model against critical field measurements or to test new model components. Data from field measurements is described in our publications and available in our databases.
Estuarine Processes Model Development
We are developing new routines within the COAWST model framework to represent coupled bio-physical processes in estuarine and coastal regions. These include routines for marsh vulnerability to waves, estuarine biogeochemistry, and feedbacks between aquatic vegetation and hydrodynamics.
U.S. Coastal Wetland Synthesis Applications Webpage Image
The USGS is assessing the physical condition of coastal wetlands and their response to external forces, using field observations and remote-sensing data. The U.S.
U.S. Coastal Wetland Geospatial Collection homepage
The collection provides a motivation for the USGS coastal wetland research and individual web apps where users can browse each CONUS-wide data separately (relative tidal elevation, unvegetated-vegetated ratio, and aboveground biomass). It also provides a Collection viewer, where users can browse the CONUS-wide collection on the same map.
The collection provides a motivation for the USGS coastal wetland research and individual web apps where users can browse each CONUS-wide data separately (relative tidal elevation, unvegetated-vegetated ratio, and aboveground biomass). It also provides a Collection viewer, where users can browse the CONUS-wide collection on the same map.
U.S. Coastal Wetland Geospatial Collection
Users can navigate the collection by clicking on the tiles on the cover page or the tabbed menu. With the Collection viewer, users can use a swipe tool to compare layers and click to see the values for each pixel. Users can also add other data to the viewer and bookmark any locations of interest.
Users can navigate the collection by clicking on the tiles on the cover page or the tabbed menu. With the Collection viewer, users can use a swipe tool to compare layers and click to see the values for each pixel. Users can also add other data to the viewer and bookmark any locations of interest.
Pre and Post Hurricane Dorian Aerial Imagery
Pre- and post-Hurricane Dorian aerial imagery showing extreme sediment transport, overwash and breaches along the barrier islands of the North Carolina coast.
Pre- and post-Hurricane Dorian aerial imagery showing extreme sediment transport, overwash and breaches along the barrier islands of the North Carolina coast.
Hurricane Florence atmospheric model
Example from development of an atmospheric model for Hurricane Florence. The images display a comparison between the control case, WRF-ROMS-SWAN modeling system and the multi-sensor (radar and rain) precipitation observations during the calibration of the model.
Example from development of an atmospheric model for Hurricane Florence. The images display a comparison between the control case, WRF-ROMS-SWAN modeling system and the multi-sensor (radar and rain) precipitation observations during the calibration of the model.
Hurricane Florence atmospheric model
Example from development of an atmospheric model for Hurricane Florence. The animation shows the changing atmospheric pressure and wind fields during the storm as simulated by the model. Arrows display wind direction, colors indicate atmospheric pressure ranging from 97,500 pascals (red) to 102,460 pascals (blue).
Example from development of an atmospheric model for Hurricane Florence. The animation shows the changing atmospheric pressure and wind fields during the storm as simulated by the model. Arrows display wind direction, colors indicate atmospheric pressure ranging from 97,500 pascals (red) to 102,460 pascals (blue).
Hurricane Florence numerical modeling
Hurricane Florence numerical modeling: Cape Fear River basin boundaries, topography, river streams and measurement locations. USGS streamflow and rain gages, and Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) gages are shown. Stream order increases going from branches to the main channel indicating merging surface water flow.
Hurricane Florence numerical modeling: Cape Fear River basin boundaries, topography, river streams and measurement locations. USGS streamflow and rain gages, and Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) gages are shown. Stream order increases going from branches to the main channel indicating merging surface water flow.
Hurricane Florence numerical modeling
Hurricane Florence numerical modeling: The Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro) is used to simulate surface and subsurface flows on land.
Hurricane Florence numerical modeling: The Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro) is used to simulate surface and subsurface flows on land.
Model output of offshore surges and waves
Hurricane Sandy (2012) modeling: Modeling can reveal the contributions from underlying processes individually. These images show contribution from offshore surge (change in water level) and offshore waves to maximum water levels (in meters) within a bay during a coastal storm.
Hurricane Sandy (2012) modeling: Modeling can reveal the contributions from underlying processes individually. These images show contribution from offshore surge (change in water level) and offshore waves to maximum water levels (in meters) within a bay during a coastal storm.
Social benefits of marshes
Photo of a boardwalk over a saltmarsh creek showing people.
Photo of a boardwalk over a saltmarsh creek showing people.
Economic benefits of marshes
Photo showing floating cages for oyster farming in a marsh creek exposed at low tide.
Photo showing floating cages for oyster farming in a marsh creek exposed at low tide.
Saltmarsh vegetation
Photo showing different species of salt tolerant plants near a saltmarsh.
Photo showing different species of salt tolerant plants near a saltmarsh.
A saltmarsh platform
Photo of a saltmarsh platform showing vegetation on on top of the banks of a tidal creek. It shows the general setting of a saltmarshes that experience wet and dry periods with the tides within a day.
Photo of a saltmarsh platform showing vegetation on on top of the banks of a tidal creek. It shows the general setting of a saltmarshes that experience wet and dry periods with the tides within a day.
Compound Flooding in the Cape Fear River Estuary
Hurricane Florence (2018) modeling: The coupled model captures the stages of compound flooding in the Cape Fear River Estuary starting with swell from offshore, followed by storm surge from the ocean side, later transitioning to flooding from land side with the storm water runoff because of rain.
Hurricane Florence (2018) modeling: The coupled model captures the stages of compound flooding in the Cape Fear River Estuary starting with swell from offshore, followed by storm surge from the ocean side, later transitioning to flooding from land side with the storm water runoff because of rain.
Study site for Edwin B. Forsythe National Wildlife Refuge, New Jersey
Edwin B. Forsythe National Wildlife Refuge, New Jersey Study SIte
Edwin B. Forsythe National Wildlife Refuge, New Jersey Study SIte
Edwin B Forsythe National Wildlife Refuge study area
Browse graphic of Edwin B Forsythe National Wildlife Refuge study area
Browse graphic of Edwin B Forsythe National Wildlife Refuge study area
Science and Products
Estuarine Processes, Hazards, and Ecosystems
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S. Geological...
Coastal Model Applications and Field Measurements- Field Measurements and Model Applications
Several components of this project are applications to evaluate the model against critical field measurements or to test new model components. Data from field measurements is described in our publications and available in our databases.
Estuarine Processes Model Development
We are developing new routines within the COAWST model framework to represent coupled bio-physical processes in estuarine and coastal regions. These include routines for marsh vulnerability to waves, estuarine biogeochemistry, and feedbacks between aquatic vegetation and hydrodynamics.
U.S. Coastal Wetland Synthesis Applications Webpage Image
The USGS is assessing the physical condition of coastal wetlands and their response to external forces, using field observations and remote-sensing data. The U.S.
The USGS is assessing the physical condition of coastal wetlands and their response to external forces, using field observations and remote-sensing data. The U.S.
U.S. Coastal Wetland Geospatial Collection homepage
The collection provides a motivation for the USGS coastal wetland research and individual web apps where users can browse each CONUS-wide data separately (relative tidal elevation, unvegetated-vegetated ratio, and aboveground biomass). It also provides a Collection viewer, where users can browse the CONUS-wide collection on the same map.
The collection provides a motivation for the USGS coastal wetland research and individual web apps where users can browse each CONUS-wide data separately (relative tidal elevation, unvegetated-vegetated ratio, and aboveground biomass). It also provides a Collection viewer, where users can browse the CONUS-wide collection on the same map.
U.S. Coastal Wetland Geospatial Collection
Users can navigate the collection by clicking on the tiles on the cover page or the tabbed menu. With the Collection viewer, users can use a swipe tool to compare layers and click to see the values for each pixel. Users can also add other data to the viewer and bookmark any locations of interest.
Users can navigate the collection by clicking on the tiles on the cover page or the tabbed menu. With the Collection viewer, users can use a swipe tool to compare layers and click to see the values for each pixel. Users can also add other data to the viewer and bookmark any locations of interest.
Pre and Post Hurricane Dorian Aerial Imagery
Pre- and post-Hurricane Dorian aerial imagery showing extreme sediment transport, overwash and breaches along the barrier islands of the North Carolina coast.
Pre- and post-Hurricane Dorian aerial imagery showing extreme sediment transport, overwash and breaches along the barrier islands of the North Carolina coast.
Hurricane Florence atmospheric model
Example from development of an atmospheric model for Hurricane Florence. The images display a comparison between the control case, WRF-ROMS-SWAN modeling system and the multi-sensor (radar and rain) precipitation observations during the calibration of the model.
Example from development of an atmospheric model for Hurricane Florence. The images display a comparison between the control case, WRF-ROMS-SWAN modeling system and the multi-sensor (radar and rain) precipitation observations during the calibration of the model.
Hurricane Florence atmospheric model
Example from development of an atmospheric model for Hurricane Florence. The animation shows the changing atmospheric pressure and wind fields during the storm as simulated by the model. Arrows display wind direction, colors indicate atmospheric pressure ranging from 97,500 pascals (red) to 102,460 pascals (blue).
Example from development of an atmospheric model for Hurricane Florence. The animation shows the changing atmospheric pressure and wind fields during the storm as simulated by the model. Arrows display wind direction, colors indicate atmospheric pressure ranging from 97,500 pascals (red) to 102,460 pascals (blue).
Hurricane Florence numerical modeling
Hurricane Florence numerical modeling: Cape Fear River basin boundaries, topography, river streams and measurement locations. USGS streamflow and rain gages, and Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) gages are shown. Stream order increases going from branches to the main channel indicating merging surface water flow.
Hurricane Florence numerical modeling: Cape Fear River basin boundaries, topography, river streams and measurement locations. USGS streamflow and rain gages, and Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) gages are shown. Stream order increases going from branches to the main channel indicating merging surface water flow.
Hurricane Florence numerical modeling
Hurricane Florence numerical modeling: The Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro) is used to simulate surface and subsurface flows on land.
Hurricane Florence numerical modeling: The Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro) is used to simulate surface and subsurface flows on land.
Model output of offshore surges and waves
Hurricane Sandy (2012) modeling: Modeling can reveal the contributions from underlying processes individually. These images show contribution from offshore surge (change in water level) and offshore waves to maximum water levels (in meters) within a bay during a coastal storm.
Hurricane Sandy (2012) modeling: Modeling can reveal the contributions from underlying processes individually. These images show contribution from offshore surge (change in water level) and offshore waves to maximum water levels (in meters) within a bay during a coastal storm.
Social benefits of marshes
Photo of a boardwalk over a saltmarsh creek showing people.
Photo of a boardwalk over a saltmarsh creek showing people.
Economic benefits of marshes
Photo showing floating cages for oyster farming in a marsh creek exposed at low tide.
Photo showing floating cages for oyster farming in a marsh creek exposed at low tide.
Saltmarsh vegetation
Photo showing different species of salt tolerant plants near a saltmarsh.
Photo showing different species of salt tolerant plants near a saltmarsh.
A saltmarsh platform
Photo of a saltmarsh platform showing vegetation on on top of the banks of a tidal creek. It shows the general setting of a saltmarshes that experience wet and dry periods with the tides within a day.
Photo of a saltmarsh platform showing vegetation on on top of the banks of a tidal creek. It shows the general setting of a saltmarshes that experience wet and dry periods with the tides within a day.
Compound Flooding in the Cape Fear River Estuary
Hurricane Florence (2018) modeling: The coupled model captures the stages of compound flooding in the Cape Fear River Estuary starting with swell from offshore, followed by storm surge from the ocean side, later transitioning to flooding from land side with the storm water runoff because of rain.
Hurricane Florence (2018) modeling: The coupled model captures the stages of compound flooding in the Cape Fear River Estuary starting with swell from offshore, followed by storm surge from the ocean side, later transitioning to flooding from land side with the storm water runoff because of rain.
Study site for Edwin B. Forsythe National Wildlife Refuge, New Jersey
Edwin B. Forsythe National Wildlife Refuge, New Jersey Study SIte
Edwin B. Forsythe National Wildlife Refuge, New Jersey Study SIte
Edwin B Forsythe National Wildlife Refuge study area
Browse graphic of Edwin B Forsythe National Wildlife Refuge study area
Browse graphic of Edwin B Forsythe National Wildlife Refuge study area