given together with the measured beach profile at the last time -step. The 

 wave height distribution across-shore for the last time-step is also shown. 



Figure 76. Reproduction of the second breakpoint bar 



480. Locations of the two bars and the amount of erosion on the fore- 

 shore were well described by the model, whereas the distinct trough shoreward 

 of the main break point was not reproduced. When the second bar appeared, sand 

 transport to the main breakpoint bar was hindered in the model and growth of 

 the main bar slowed. 



481. As previously mentioned, between the shoreward break point x^, 

 and the point where the transport rate attains a minimum in the reformed wave 

 zone x^ , a power function was used to describe the decrease in transport 

 rate. An exponent of 0.5 proved adequate, although the calculation was not 

 sensitive to changes in this value. Changes in the exponent did not affect 

 the shape or size of the outer bar but did influence somewhat the location of 

 the inner bar. A larger value of the exponent caused the inner bar to move 

 farther seaward, whereas a smaller value hindered seaward bar movement. From 

 the point of wave reformation Xj. shoreward, an exponential decay was used, 

 thus introducing another spatial decay coefficient u . Typical coefficient 



202 



