Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/3373
Title: Wave forecasting relationships for the Gulf of Mexico
Authors: United States. Army. Office of the Chief of Engineers
Bretschneider, Charles L., 1920-
Keywords: Water waves
Winds
Gulf of Mexico
Hindcasting
Forecasting
Publisher: United States, Beach Erosion Board
Engineer Research and Development Center (U.S.)
Series/Report no.: Technical memorandum (United States. Beach Erosion Board) ; no. 84.
Description: Technical Memorandum
From the Introduction: This report describes the development and application of a method for computing wind wave data over the Continental Shelf along the United States coast of the Gulf of Mexico. Methods for forecasting deep-water wind waves and wind waves in shallow water of constant depth, such as shallow lakes and bays, are already available (8, 9, 12,16)*. The problem of the Continental Shelf of the Gulf of Mexico, however, is more complex, since here the waves may generate originally in deep water, but then, under the continued influence of wind, are propagated shoreward over the Continental Shelf where bottom friction and type of bottom profile become important. Because of the variety of initial deep-water conditions and bottom profiles, each location requires separate treatment. A set of generalized forecasting curves is required for each location and each direction to bring the waves in over the shallow sloping bottom to the desired depth. Using deep-water forecasting relationships and taking bottom friction into account, a generalized set of dimensionless forecasting relationships is prepared for each of the five locations (Figure 1) in the Gulf of Mexico for which statistical deep-water wave data are compiled (1, 2, 3, 4, 5). The forecasting curves are intended for the most frequent minimum fetch and corresponding wind speed for various deep-water wave height ranges and average bottom conditions of various directions. For the cases of winds parallel to the coast or from land to sea the curves are applicable to all water depths. However, for the case of winds blowing from sea toward land, the forecasting relationships are satisfactory only for depths of about 20 feet or greater, although the technique has been stretched to a depth of 12 feet for cases where winds are not too high. At depths of about 20 feet or less the bottom slope changes too rapidly for the theory to apply, and longer period swell will be breaking in the surf zone, thereby obscuring the wind wave pattern. Examples on the use of the forecasting graphs are given in Appendix A. It must be emphasized that a certain amount of averaging is required to simplify the problem, and the forecasting curves must be used with discretion for other than nearby locations, where refraction becomes important. The forecasting curves result in wave heights to within + or - 10 percent of the average condition, except in the extreme case of shoal areas.
Rights: Approved for Public Release, Distribution is Unlimited
URI: http://hdl.handle.net/11681/3373
Appears in Collections:Technical Memorandum

Files in This Item:
File Description SizeFormat 
BEB-TM-84.pdf3.37 MBAdobe PDFThumbnail
View/Open