Modeling the Effects of Waves and Breach Geometry on the Hydrodynamics of a Bar-Built Estuary Along California's Coast
Abstract
Bar-built estuaries are found all over the world as a result of ocean waves and rivers colliding and establishing a coastal barrier that can open and close intermittently. These uncertain morphological and hydrodynamic events affect littoral operations within these areas by the barriers constant evolving state in shape, size, depth, and hydrodynamic condition. Carmel River State Beach (CRSB) is a perched bar-built estuary that undergoes morphological transitions between breaching and closure, intermittently opening the ephemeral Carmel River to the Pacific Ocean. Perched bar-built estuaries, which continually have water levels above the ocean, have been difficult to model, and understanding the interaction of the waves within the estuary continues to be a challenge. This study sought to understand the impact of ocean waves on a bar-built estuary during a breach period. Delft3D internally coupled with SWAN was used to simulate environmental conditions at CRSB during March 2020, when observations of a breach event described the morphological state of the channel. Findings suggest that northerly swell waves strongly influence CRSB. Though periods of high tide saw tidal oscillations inside the estuary, they were negligible during low tides and periods of heavy river discharge. These findings help determine the feasibility of this modeling system to predict hydrodynamics around bar-built estuaries and can beused to assess the relative importance of waves and river discharge.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2021
- Accession Number
- AD1164885
Entities
People
- Alexander W. Cavins
Organizations
- Naval Postgraduate School