(j ) Summary of Test Results . The model accurately repro- 

 duced existing shoaling patterns (i.e., a bar across the entrance) as 

 shovm in Figure 5-6. The originally proposed jetty arrangement with 

 the entrance oriented to the southwest resulted in shoaling in the har- 

 bor entrance. The best jetty configuration tested (shown in Fig. 5-7) 

 prevented shoaling, provided adequate wave protection, and allowed the 

 passage of floodflows and ice. 



6. Recommendations for Further Research . 



Considerable work is obviously required before the design and opera- 

 tion of quantitative movable-bed scale-model investigations of coastal 

 sediment transport become routine. However, considerable optimism re- 

 garding the success of such an endeavor is apparently justified. Because 

 of the pressing national need for shoreline protection and preservation, 

 as well as the need to acquire a reliable assessment of the effects of 

 coastal and offshore construction (such as deepwater superports, offshore 

 airports, or offshore nuclear powerplants) on shoreline evolution, it is 

 imperative that satisfactory accuracy in modeling capability be developed 

 to the fullest extent possible. A few specific areas requiring further 

 research are: 



(a) Determine the effect of model sediment-size distri- 

 bution on equilibrium beach profiles and longshore sediment 

 transport. Since the median diameter of model sediments is 

 important, the immediate questions are whether the model sedi- 

 ment can be of uniform size, must the sediment have precisely 

 the same particle-size distribution as the prototype, or is 

 some scaling relation required other than merely that involving 

 the mean particle diameter. 



(b) Perform a comprehensive and thorough experimental and 

 analytical investigation of the scale-model laws proposed by 

 Noda (1972). These laws show promise in some areas but are 

 lacking in others; however, the approach appears to have merit 

 and should be pursued further. 



(c) Perform additional experimental and analytical tests 

 (after completion of (a) and (b) above) to derive a recommended 

 scale-model law based on similitude of equilibrium beach pro- 

 files and, if possible, on longshore transport rates. 



(d) Perform the required prototype data acquisition and 

 analysis effort for a suitable site. 



(e) Attempt to verify the laws developed in (c) above 

 with the data obtained in (d). 



(f) Investigate the effects of model linear-scale dis- 

 tortion and bottom material on edge wave development and rip 

 current intensity, and attempt to ascertain when (if at all) 

 their reproduction in the model is necessary. 



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