Hindcasting of decadal‐timescale estuarine bathymetric change with a tidal‐timescale model

Journal of Geophysical Research F: Earth Surface
By: , and 

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Abstract

Hindcasting decadal-timescale bathymetric change in estuaries is prone to error due to limited data for initial conditions, boundary forcing, and calibration; computational limitations further hinder efforts. We developed and calibrated a tidal-timescale model to bathymetric change in Suisun Bay, California, over the 1867–1887 period. A general, multiple-timescale calibration ensured robustness over all timescales; two input reduction methods, the morphological hydrograph and the morphological acceleration factor, were applied at the decadal timescale. The model was calibrated to net bathymetric change in the entire basin; average error for bathymetric change over individual depth ranges was 37%. On a model cell-by-cell basis, performance for spatial amplitude correlation was poor over the majority of the domain, though spatial phase correlation was better, with 61% of the domain correctly indicated as erosional or depositional. Poor agreement was likely caused by the specification of initial bed composition, which was unknown during the 1867–1887 period. Cross-sectional bathymetric change between channels and flats, driven primarily by wind wave resuspension, was modeled with higher skill than longitudinal change, which is driven in part by gravitational circulation. The accelerated response of depth may have prevented gravitational circulation from being represented properly. As performance criteria became more stringent in a spatial sense, the error of the model increased. While these methods are useful for estimating basin-scale sedimentation changes, they may not be suitable for predicting specific locations of erosion or deposition. They do, however, provide a foundation for realistic estuarine geomorphic modeling applications.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Hindcasting of decadal‐timescale estuarine bathymetric change with a tidal‐timescale model
Series title Journal of Geophysical Research F: Earth Surface
DOI 10.1029/2008JF001191
Volume 114
Issue F4
Year Published 2009
Language English
Publisher Amercan Geophysical Union
Contributing office(s) California Water Science Center
Description 15 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Geophysical Research F: Earth Surface
Time Range Start 1866-12-31
Time Range End 1887-12-31
Country United States
State California
Other Geospatial Suisun Bay