- Waikiki - Analysis of an Engineered Shoreline

Date
2002-12
Authors
Miller, Tara L.
Contributor
Advisor
Fletcher, Charles
Department
Geology & Geophysics
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
University of Hawaii at Manoa
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Short-term and long-term shoreline change at Waikiki Beach is analyzed to enhance resource management. Bi-monthly beach profiles reveal short-term variations of the shoreline. Increased wave heights from south swells between May and October often correspond to a period of volume increase, while short-period wind waves predominating between November and April regularly correspond to volume losses. A total mean volume of 167,000 m3 is estimated for Waikiki Beach, with an uncertainty of 15 to 40%. A net volume loss of ~5,200 m3 is found between October 2000 and May 2002. The Royal Hawaiian littoral cell accounts for 93% of the loss. Historical aerial photographs and NOAA T-sheets establish a 76-year shoreline history (1925-2001). The shoreline has migrated a mean distance of 12 m seaward over this period, reflecting the high level of human intervention. Likewise, overall beach width has increased by 32% since 1951. Four of seven littoral cells, however, are characterized by erosion over more recent time scales, showing a mean erosion rate of 0.3 ± 0.1 m/yr. Of the remaining three littoral cells, two have experienced long-term accretion and one has exhibited stability. A relationship between beach width and corresponding sand volume change, established from beach profile data, is applied to historical shoreline changes to establish a history of sand volume fluctuations. Early volume fluctuations are traced to beach nourishment, typically with subsequent beach loss. Volume gains are documented across the entire shoreline between 1975 and 1985. Widespread chronic erosion characterizes the years after 1985. Despite frequent beach nourishment, a sediment budget for Waikiki reveals a sand volume deficit of at least 77,000 m3 for the time period between 1951 and 2001, owing to permanent offshore losses.
Description
xiv, 107 leaves
Keywords
Citation
Extent
Format
Geographic Location
Time Period
Related To
Theses for the degree of Master of Science (University of Hawaii at Manoa). Geology and Geophysics; no. 3750
Table of Contents
Rights
All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.