Accession Number:

ADA155610

Title:

Coastal Erosion along Monterey Bay.

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1985-03-01

Pagination or Media Count:

108.0

Abstract:

Permanent beach erosion in Southern Monterey Bay, CA, is episodic, occurring infrequently when high tides coincide with stormy weather which allows wave action to erode the toe of the cliffs. This thesis uses precise aerial photogrammmetric techniques to measure cliff recession from 1946 through 1984. Maximum erosion occurs in the vicinity of Fort Ord 7.3 ft.yr and decreases to the south. A model is developed to predict cliff erosion based on the hypothesis that erosion occurs only when the water level due to combined tides, wave set-up and run-up exceeds the toe the cliff elevation. The model combines predicted tidal elevations and wave heights. Shallow water wave heights at various locations are calculated by transforming deep-water directional wave spectra provided by the Fleet Numerical Oceanography Center. Refraction of the wave energy is responsible for the variabillity of erosion rates along the shore. The bathymetry of Monterey Bay is such that the refracted wave energy is greater in the Fort Ord area than to the south. The erosion model was calibrated using the spectral wave climatology and aerial photographs covering an 18 year period. The model qualitatively replicates the temporal variability of the measured recession rates and gives a reasonable prediction of the spatial variation of the mean recession rates. Keywords Errors, Cliff recession.

Subject Categories:

  • Cartography and Aerial Photography
  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE