NO. 50 - August 1954 



II-B "Statistical Significance of Beach Sampling Methods" by 

 ■ D W. C. Krumbein 



Beach sampling methods in terms of statistical prin- 

 ciples are reviewed for the purpose of suggesting 

 tentative plans for improving the representativeness 

 in samples. Statistical methods used are discussed. 

 Results of the study indicate no radical revisions 

 of current sampling procedures are needed, but 

 recognition of explicit design elements in the 

 sampling plan can result in greater reliability of 

 the data for comparable expenditure of time and 

 effort. 



NO. 51 - October 1954 



II-A "Generation of Wind Waves Over a Shallow Bottom" by 

 C. L. Bretschneider 



A method is presented for predicting properties of 

 waves generated in shallow water, obtained by a 

 numerical combination of the relationships for (deep 

 water) ocean wave generation devised by Sverdrup and 

 Munk and revised by Bretschneider, with the theory of 

 wave energy losses in shallow water devised by Putnam 

 and Johnson and revised by Bretschneider and Reid. 

 The method is essentially that of successive approxi- 

 mations vrtierein wave energy is added due to wind stress 

 and subtracted due to bottom friction and percolation. 



NO. 52 - December 1954 



I-C "Laboratory Study of Effect of Tidal Action on Wave-Formed 



Beach Profiles" by George M. Watts and Robert F. Dearduff 



Some two-dimensional tests to study equilibrium profiles 

 of beaches previously made in a laboratory wave tank 

 utilizing uniform wave trains were repeated introducing 

 a tidal system and resulting profiles compared. Results 

 indicate that introduction of tidal action causes no 

 appreciable changes in foreshore and offshore slopes, 

 but greater movement of material throughout the profile 

 results in proportion to the tidal range, creating 

 higher beach berms and recession of the shoreline. 

 Formation of offshore bars and troughs inherent in the 

 non-tidal tests due to wave reflections was inhibited 

 by introduction of the tidal system. 



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