Accession Number : ADA184055

Title :   Duration of Extreme Wave Conditions.

Descriptive Note : Final rept.,

Corporate Author : COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS

Personal Author(s) : Smith,Orson P

PDF Url : ADA184055

Report Date : Jun 1987

Pagination or Media Count : 146

Abstract : Statistical trends of the duration of extreme wave conditions, as characterized by hindcast wave information, are investigated at five sites along the coastline of the United States (three on the Atlantic coast and two on the Pacific coast). A review of pertinent statistical concepts and water wave characterization conventions and terminology is followed by a description of the Wave Information Studies Program. The database of hindcast wave information in shallow water created by this program is applied to develop a method of identification of extreme events and definition of their duration, based on exceedance of a threshold or zero moment wave heights. The number of events identified is found to be proportional to the percent exceedance of the specified threshold, regardless of geographical location. The External Type I distribution is found to be superior to the Weibull distribution as a model for both distribution of durations and peak zero moment wave heights of extreme events identified. A regression analysis of duration with various parameters representing peak wave conditions reveals only a weak linear relation with peak zero moment wave height and little evidence of a linear relation with any other parameter investigated. The assumption of independence of duration from peak wave conditions is proposed as an expedient method for estimating durations above a specified threshold, given a peak wave condition.

Descriptors :   *OCEAN WAVES, ATLANTIC OCEAN, COASTAL REGIONS, DISTRIBUTION, TIME, WAVES, IDENTIFICATION, PACIFIC OCEAN, PEAK VALUES, DATA BASES, EXTERNAL, GEOGRAPHY, LINEARITY, REGRESSION ANALYSIS, RANGE(EXTREMES), HEIGHT, STORMS, SURGES, SHALLOW WATER, PATTERNS, STATISTICS, WATER WAVES, LOW STRENGTH, UNITED STATES, WAVES, STATISTICAL DISTRIBUTIONS, WEIBULL DENSITY FUNCTIONS

Subject Categories : Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE