Parametsr 



Meters (Feet) 



Maximum astronomic high water 



+3.4 (+11.1) 



Mean spring high water 



+2.8 (+9.3) 



Mean high water 



+2.7 (+8.8) 



Mean tide level 



+ 1.3 (+4.4) 



Mean low water 



0.0 (0.0) 



Mean spring low water 



-0.2 (-0.6) 



Minimum astronomic high water 



-0.7 (-2.3) 



Swl's of 0.0, +2.7. +3.7, and +4.1 m (0.0, +8.8, +12.0, and +13.6 ft) were 

 selected by NED for use in testing the Camp EUis Beach model. The 

 0.0- and 2.7-m (0.0- and +8.8-ft) values were representative of mlw and mean 

 high water (mhw), respectively, and were used for most model tests. The 

 +3.7- and +4.1-m (+12.0- and +13.6-ft) values were used while testing severe 

 storm wave conditions. These swl's coincided with major storms at Camp 

 EUis Beach (Hubertz and Curtis 1993) that occurred in 1991 (Halloween Storm 

 of 1991) and 1978 (Blizzard of 1978), respectively. 



Factors Influencing selection of test wave characteristics 



In planning the testing program for a model investigation of wave-action 

 problems, it is necessary to select heights, periods, and directions for the test 

 waves that wiU allow a definition of existing conditions, realistic testing of 

 proposed improvement plans, and an accurate evaluation of the elements of the 

 various proposals. Surface-wind waves are generated primarily by the interac- 

 tions between tangential stresses of wind flowing over water, resonance 

 between the water surface and atmospheric turbulence, and interactions 

 between individual wave components. The height and period of the maximum 

 significant wave that can be generated by a given storm depend on the wind 

 speed, the length of time that wind of a given speed continues to blow, and the 

 distance over water (fetch) which the wind blows. Selection of test wave 

 conditions entails evaluation of such factors as: 



a. Fetch and decay distances (the latter being the distance over which 

 waves travel after leaving the generating area) for various directions 

 from which waves can approach the problem area. 



b. Frequency of occurrence and duration of storm winds from the different 

 directions. 



c. Alignment, size, and relative geographic position of the navigation 

 structures. 



Chapter 3 Test Conditions and Procedures 



15 



