Date of Award

Spring 2005

Document Type

Thesis

Degree Name

Master of Science in Environmental Policy Studies - (M.S.)

Department

Chemistry and Environmental Science

First Advisor

Nancy L. Jackson

Second Advisor

Karl F. Nordstrom

Third Advisor

Maurie J. Cohen

Abstract

Construction of bulkheads as a method of shore protection is common on the bay shoreline of Fire Island, New York but there are few studies that assess the effects of these structures on beach change in estuarine and lagoon environments. A short-term field study was conducted at Cherry Grove on Fire Island to assess the effect of a bulkhead on the fronting profile and to the adjacent beaches on the east side of the bulkhead. Data on winds, waves, and currents were gathered daily at high water. Data on profile change and depth of sediment activation were gathered at low water.

Wave heights ranging from 0.22 m to 0.27 m were recorded in front of the bulkhead during the field investigation. The northwest winds (average speed of 7.1 mIs) resulted in volumetric loss of sediment on the adjacent beach. The northeast winds (average speed of 6.6 mIs) resulted in considerable sediment deposition on the adjacent beach. Effects of the bulkhead during northwest winds were minor, while during northeast winds it acted as a trap for sediments transported by the longshore current. It was found that even the small volumetric changes on the adjacent beach can cause large horizontal displacement of the shoreline.

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