Littoral environment observations and beach changes along the southeast Florida coast / by Allan E. DeWall.

Abstract

Beach changes Boca Raton, Florida Erosion side // necessary and Identity by block number) Hollywood, Florida Jupiter, Florida Littoral environment observations Offshore protection Wave climate Waves 20. ABSTRACT fConrlnue on reverse aide II necessary and Identify by block number)Daily and weekly surveys and observations of the beach and nearshore were made at Jupiter, Boca Raton, and Hollywood, Florida, for 4% years between 1969 and1973. During this relatively stormfree period, mean annual breaker height varied from a high of 0.9 meter at Jupiter, the northernmost site, to 0.5 meter at Hollywood, the southernmost site.This decrease in wave energy reaching the shoreline is attributed to the varying protection afforded by the Bahama Banks, 80 kilometers offshore of Hollywood. Wave and longshore (Continued) DD ,7> EDITION OF I NOV 65 IS OBSOLETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (Whan Data Ente IINPl.A.'^ClTFTFn SECURITY CLASSIFICATION OF THIS PAGE(1Rian Datm Bnland) current directions were observed to change seasonally, with directions from the northeast dominating during October through March and from the southeast during April through September.Potential gross longshore transport rates, estimated from these data, ranged from 1,800,000 cubic meters per year at Jupiter to 1,200,000 cubic meters per year at Boca Raton, to 480,000 cubic meters per year at Hollywood.The magnitude of beach changes, as defined by shoreline position and sand volume on the beach, decreased from north to south and is relatively low compared with typical U. S. east coast beaches. Contributing factors include the sheltering effect of the Bahama Banks, the lack of significant storms, and the underlying coquina limestone which characteristically crops out just below the MSL shoreline, forming a protective reef that effectively retards erosion.Beach changes were seasonal in nature, but were reversed at Boca Raton, where beach width and sand volume were highest during the winter months.Seasonal beach changes were two to three times greater than year-to-year changes. The average unit volume change rate above MSL was -1.8 cubic meters per meter per year at Jupiter, +1.0 cubic meter per meter per year at Boca Raton, and +0.1 cubic meter per meter per year at Hollywood.Corresponding MSL shoreline migration rates were -0.1 meter per year at Jupiter, +0.46 meter per year at Boca Raton, and -0.9 meter per year at Hollywood. Nearshore volume changes between surveys at Boca Raton were not related to above MSL beach changes. UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGEfWhO" D«(a Entared) .

Validation of Visually Observed Waves with the Recorded Waves on the Southwest Coast of India

“…2). Generally, wave rose diagrams are prepared separately for height and period [18,19]. Combined wave rose diagrams for height and period are prepared to achieve a check on the data quality.…”