60 



so that gF/U^ = 544.4 and gh/U^ = 0.1089. According to Eq. 5.10 waves will 

 be generated whose heights are 2.06 m, and according to Eq. 5.13 the period 

 will be 6.3 s. 



Next consider the same storm after aim rise in sea level. Following 

 the same procedure as before yields H = 2 . 18 m and T = 6.4 s, or an 

 increase in wave height and period of 5.8% and 1.6% respectively. If the 

 continental shelf is 150 km wide and has a friction coefficient f = 0.01, 

 the loss in wave height due to bottom friction is calculated using Eq. 5.18 

 and the wave height in the nearshore is found to be H = 0.82 m for the case 

 without sea level rise. With the initial wave conditions for the 1 m sea 

 level rise, the wave height on the inner shelf is found to be 0.96 m, or a 

 16.6% increase in wave height due to the combined effects of sea level rise 

 during generation (slight) and reduced bottom friction on the shelf 

 (marked) . 



More detailed numerical models for wind-wave generation have been 

 developed, e.g., Cardone et al . (1976) and Resio (1981). Several models 

 have been intercompared by the Sea Wave Modeling Project (SWAMP, 1985) but 

 without definite conclusions due to lack of data. Cardone (1986) concludes 

 that the level of error in wave height, period, and direction is on the 

 order of 10% if high quality wind data are available. However, such data 

 seldom are, and for predictive purposes the use of less accurate models for 

 representing winds is often necessary. 



5.4 RESEARCH NEEDS 



From the previous analyses, it appears that long-term sea level rise 

 will have a measureable effect on storm surge and wind wave generation only 

 in locations where the continental shelf is shallow and its length fixed by 

 a naturally hard shoreline, or one that has been stabilized with 

 structures. Therefore, the aspects of storm surge and wind-wave generation 

 that require research have less to do with long-term sea level rise, than 

 with the basic phenomena themselves. Storm surge has received intensive 

 theoretical and numerical study over the past three decades, and several 

 sophisticated numerical models exist. However, there is a conspicuous lack 

 of field measurements of hurricane and extratropical storm surge with which 

 to calibrate and verify these models. Required are concurrent time series 



