SENSITIVITY ANALYSIS OF WATER LEVELS AND WAVES IN THE CARMEL RIVER STATE BEACH TO CHANGING BOUNDARY AND MORPHOLOGICAL CONDITIONS IN DELFT3D: CARMEL RIVER LAGOON

Bar-built estuaries are common worldwide along many of the coastlines that the Navy and Marine Corp operate in, however, modeling capabilities for morphologically variable systems are limited and immature in development. Climate change, major precipitation events such as severe storms and cyclones, La Nina, and human interactions can impact these bar-built estuaries and change the operating environment, both on seasonal and yearly timescales. This study uses the numerical model Delft3D to assess sensitivities of the processes driving breaching events at the Carmel River State Beach. This sensitivity analysis varies boundary conditions and morphology inputs based on in-situ environmental data from the March 2020 breaching event. Hydrological sensitivity analysis revealed that when the Carmel River experiences low river discharge, the offshore wave and tidal energy had a larger impact on the lagoon water level and conversely, when river discharge is maximized, despite the wave height, river discharge dominates the processes affecting water level in the lagoon. Both increased discharge and increased wave heights increased the mean water level in the lagoon. The morphologic analysis showed that the presence of a berm, or building sandbar, also increased the mean water level within the lagoon. Delft3D also captures simple dynamics of sediment transport and provides realistic results for sedimentation and erosion, as compared to the observations from March 2020.

Department dc:contributor.department

Oceanography (OC)

Grantor dc:publisher

Monterey, CA; Naval Postgraduate School

Year dc:date.issued

2023

Author dc:creator

• Williamson, Cynthia F.

Advisors dc:contributor.advisor

• Orescanin, Mara S.
• Velasquez Montoya, Liliana, United States Naval Academy

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Handle dc:identifier.uri

https://hdl.handle.net/10945/72293

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/72293