Morphological response of variable river discharge and wave forcing at a bar-built estuary
Author
Orescanin, Mara M.
Coughlin, Jillian
Young, Walter R.
Date
2021-05-29Metadata
Show full item recordAbstract
Observations of morphological evolution at Carmel River State Beach, Carmel, CA, USA, were made during two winter periods where the estuary underwent transitions from closed to open states episodically during each observation period. However, each winter was climatologically distinct: the first (Dec 2016–May 2017) was a high river discharge year (several events >200 m³ /s) with westerly offshore waves and the second (Dec 2017–May 2018) was a low river discharge year with northwesterly offshore waves. The morphological response of the beach was measured using Structure-from-Motion from both aircraft and unmanned aerial vehicles (UAVs) and shows two distinct seasonal trends. The first (in 2016–2017) indicates rapid (hours) and frequent (days-weeks) migration of the river breach channel across the span of the beach. The second (in 2017–2018) indicates no migration of the initial breach channel, despite multiple breach events. Analysis of the offshore wave energy using the Coastal Data Information Program (CDIP) hindcast model results indicate a stronger longshore wave radiation stress during the migratory breach year. In addition, discharge rates during this year were more than three times stronger than the non-migratory year, indicating a stronger offshore jet from the breach site. These observations support the hypothesis that migration requires both a strong river discharge and a longshore wave radiation stress component.
Description
17 USC 105 interim-entered record; under review.
The article of record as published may be found at https://doi.org/10.1016/j.ecss.2021.107438
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.Collections
Related items
Showing items related by title, author, creator and subject.
-
MORPHOLOGY CHANGES TO CARMEL RIVER STATE BEACH IN RELATION TO WAVES AND RIVER DISCHARGE
Coughlin, Jillian N. (Monterey, CA; Naval Postgraduate School, 2019-06);Morphological changes to beaches are the result of sediment transport via wind forcing, water flow, and human interference. Extreme morphological change to beaches occurs when a breach occurs across a beach. Each year, an ... -
TRACKING THE MORPHOLOGICAL CHANGES DURING A DRY VERSUS RAINY SEASON AT THE PAJARO RIVER ESTUARY USING UAS
Helms, Joshua J. (Monterey, CA; Naval Postgraduate School, 2023-12);Drastic morphological change occurs annually at the ephemeral river at Pajaro River beach as an inlet is created upon breaching to the Monterey Bay. This inlet breach, and subsequent migration of that inlet, affects the ... -
IDENTIFYING SEDIMENT TRANSPORT POTENTIAL AND VELOCITY PROFILES IN THE CARMEL RIVER USING AN ADP
McPherson, Tyonna N. (Monterey, CA; Naval Postgraduate School, 2020-12);The Carmel River runs 58 km from the Santa Lucia Mountains through the Carmel Valley, eventually stopping at a lagoon on Carmel River State Beach. During the winter months, the river breaches through the lagoon, allowing ...