57 



from which it is difficult to immediately draw firm conclusions, 

 for positive ri(Jl) , from Eq. 5.7 we know that 



However, 



< 



1 - 



B 



h m 



(-0- - 1) 

 mri(Jt) B 



(5.9) 



B 



Quite sophisticated 2-D (planform) and multiple layer numerical models 

 have been developed since the mid-1950s, which treat more realistic bottom 

 topography and boundary geometry, see e.g., Jelesnianski (1965), Reid and 

 Bodine (1968) , Heaps and Jones (1975) , Wang and Connor (1975) , Wanstrath et 

 al. (1976), Forristall et al. (1977), Chen et al. (1978) and Thacker 

 (1979) . The caliber of these models has outrun the quantity and quality of 

 available field data with which to verify them. Complicated numerical 

 models also do not lend themselves easily to examining the general 

 interaction of the forcing mechanisms and surge response, and it may be 

 necessary to look for ways to parameterize and scale the models to extract 

 the effects of sea level rise on storm surge. 



5.3 WAVE CHARACTERISTICS 



The characteristics of waves generated in deep water should not change 

 in response to sea level rise. However, for the same wind speeds and fetch 

 lengths, waves generated over the continental shelf and shallower water 

 will be higher and longer due to the reduced effects of bottom friction and 

 steepness -limited breaking. From the Shore Protection Manual, U.S. Army 

 Corps of Engineers (1984) the wave height H generated by wind speed U 

 blowing over a fetch length F in water depth h is given by the expression 



^ =0.238 tanh [0.53(^) 

 U U 



0.75 



] tanh 



(5.10) 



In shallow water this reduces to 



