PROGRESS REPCMITS ON RESEARCH SPONSORED BY 

 THE BEACH EROSION BOARD 



Summaries of progress made during the past year on the several 

 research contracts in force between universities or other institutions 

 and the Beach Erosion Board, together with brief statements as to the 

 status of some research projects being prosecuted in the laboratory of 

 the Beach Erosion Board, are presented below. These summaries supple- 

 ment and continue those contained in prior issues of the Bulletin. 



I. University of California, Contract DA-49-055-eng-8. Sources of 

 Beach Sand . 



Seasonal sampling of Pt. Reyes beach and other beaches in the San 

 Francisco area was continued, A report, "Changes in Configuration at 

 Pt. Reyes Beach, California 1955-56" was published as Technical Memo- 

 randum No. 91. The report summarized the sand sample data at Pt. Reyes 

 over a year's period, and presents one type of statistical analysis of 

 the data. The report indicates that the beach is highly variable, 

 with the sand ranging from relatively coarse in the fall to considerably 

 less coarse in late winter. Also included in the report are data on 

 the cut-and-fill of the beach area over a aj-year period, 



II. Massachusetts Institute of Technology, Contract DA-49-055-eng-16 . 

 Sorting of Beach Sand by Waves. 



Additional data have been gathered on a flatter slope (1 on 25), 

 particularly with regard to the incipient and equilibrium conditions 

 and the mean net sediment velocity, primarily for waves in the 0.005 to 

 0.01 steepness range. A report on these tests is scheduled for sub- 

 mission shortly. 



III. University of California, Contract DA-49-055-eng-17. Fundamental 

 Mechanics of Sand Movement by Waves. 



Additional data on the flow pattern near the bed under oscillating 

 wave motion have been gathered by use of an oscillating bed. These 

 data have been used in conjunction with a theoretical analysis to define 

 coefficients for a description of bottom flow conditions for turbulent 

 flow for the case of small amplitude waves and relatively deep water; 

 a report dealing with this work was published as Technical Memorandum 

 No. 97, 



IV. University of California, Contract DA-49-0S5-eng-31. Wind Action 

 Over Shallow Water. 



Experimental work on the effect of bottom roughness in wind set-up 

 and wave generation was performed using equally spaced strips of window 

 screen serving to represent the roughness. Results of this study show 



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