Geomorphic Change

Changes to the geomorphic structure of estuaries impact hydrodynamics, ecosystem function, and navigation. We are implementing new methods of observing and modeling these changes using innovative field and computational approaches.

Detecting changes to estuarine geomorphology is challenging due to multiple timescales of forcing and the complexity of estuarine sediment transport. Traditional vessel-based bathymetric mapping is difficult due to shallow depths, while airborne LiDAR can be hampered by low water clarity. Over decadal timescales, repeat surveys using these methods can resolve bathymetric changes. Over shorter event timescales, different methods are necessary, including bed-mounted altimeters, erosion pins, and high-resolution hydrodynamic measurements. While these methods can be spatially limited, they can resolve the centimeter-scale changes that occur in estuaries over tidal-to-annual timescales.

geomorphic simulation

Simulation results for geomorphic change in Suisun Bay, CA (Ganju and Schoellhamer, 2010)

Modeling estuarine geomorphology is fraught with uncertainty due to unknown initial conditions and model limitations. However, applying models under various forcing scenarios can elucidate geomorphic processes and yield clues to the long-term geomorphic trajectory of estuarine features. We are using realistic and idealized model configurations to understand the mechanisms that control geomorphology under past, present, and future conditions.

Publications:

Beudin, A., N. K. Ganju, Z. Defne, and A. L. Aretxabaleta, 2017, Physical response of a back-barrier estuary to a post-tropical cyclone, J. Geophys. Res. Oceans, 122, 5888–5904, doi:10.1002/2016JC012344. (beudin_et_al_response.pdf)

Ganju, N.K., Suttles, S.E., Beudin, A., Nowacki, D.J., Miselis, J.L. and Andrews, B.D., 2016. Quantification of storm-induced bathymetric change in a back-barrier estuary. Estuaries and Coasts, pp.1-15. (ganju_et_al_quantification.pdf)

Miselis, J.L., Andrews, B.D., Nicholson, R.S., Defne, Z., Ganju, N.K. and Navoy, A., 2015. Evolution of mid-Atlantic coastal and back-barrier estuary environments in response to a hurricane: Implications for barrier-estuary connectivity. Estuaries and Coasts, pp.1-19. (miselis_et_al_barnegat.pdf)

Ganju, N.K., Jaffe, B.E., and Schoellhamer, D.H., 2011, Discontinuous hindcast simulations of estuarine bathymetric change: a case study from Suisun Bay, California. Estuarine, Coastal and Shelf Science, 93, 142-150. (ganju_et_al_discontinuous.pdf)

Ganju, N.K., and Schoellhamer, D.H., 2010, Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply. Estuaries and Coasts, 33, 15-29. (ganju_schoellhamer_scenarios.pdf)

Ganju, N.K., and Schoellhamer, D.H., 2009, Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for robust simulation of geomorphic evolution. Continental Shelf Research, 29, 148-158. (ganju_schoellhamer_calibration.pdf)

Ganju, N.K., Schoellhamer, D.H., and Jaffe, B.E., 2009, Hindcasting of decadal-timescale estuarine bathymetric change with a tidal-timescale model. Journal of Geophysical Research-Earth Surface, 114, F04019, doi: 10.1029/2008JF001191. (ganju_et_al_hindcasting.pdf)

Ganju, N.K., Knowles, N., and Schoellhamer, D.H., 2008, Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations. Journal of Hydrology, 349, 512-523. (ganju_et_al_loads.pdf)

Ganju, N.K., and Schoellhamer, D.H., 2006, Annual sediment flux estimates in a tidal strait using surrogate measurements. Estuarine, Coastal and Shelf Science, 69, 165-178. (ganju_schoellhamer_benicia.pdf)

Ganju, N.K., Schoellhamer, D.H., Warner, J.C., Barad, M.F., and Schladow, S.G., 2004, Tidal oscillation of sediment between a river and a bay: a conceptual model. Estuarine, Coastal and Shelf Science, 60(1), 81-90. (ganju_et_al_oscillation.pdf)

 

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://woodshole.er.usgs.gov/project-pages/estuaries/geomorphicchange.html
Page Contact Information: Feedback
Page Last Modified: Wednesday, 14-Feb-2018 16:26:18 EST (GW)