Short-period wave-height tests 



Wave-height tests for existing conditions and the improvement plan 

 were conducted for the selected test waves and directions listed in Chap- 

 ter 3. Wave gage locations are shown in Plates 1 and 2. 



Sediment tracer tests 



Riverine sediment tracer tests were conducted for existing conditions 

 and the offshore breakwater plan using river discharges ranging from 

 7,000 to 41,000 cfs. Tracer material was introduced into the model in the 

 lower reaches of the river to represent bed-load sediment. These tests 

 were also conducted with various wave conditions from west and west- 

 northwest superimposed for existing conditions and the offshore breakwa- 

 ter plan. Wave-induced sediment tracer tests were also conducted for 

 waves from northwest and southwest. Tracer material was introduced 

 north and south of the cove to represent sediment along those shorelines. 



Long-period wave tests 



Long-period (60 to 200 sec) wave tests were conducted for the break- 

 water improvement plan and compared with tests conducted previously 

 (Bottin, Acuff, and Markle 1988) for existing conditions. These tests 

 were conducted using test waves from the west. Two types of tests in- 

 volved with investigating long-period waves are as follows: 



a. Frequency response tests involved the placement of wave sensors at 

 strategic locations throughout the harbor to measure the amplitude 

 of the oscillations. By plotting the ratio of the measured wave 

 height at each gage to the incident wave height (response factor) 

 versus the wave periods tested, frequency response curves showing 

 resonant peaks were obtained. 



b. Surface-float tests were conducted using small white squares of 

 styrofoam confetti to determine oscillation patterns. The confetti 

 was spread over the surface of the channel and basins, and 

 subsequent movement by each wave period was observed. Through 

 visual observations, the oscillation patterns and location of nodes 

 and antinodes were determined. 



Wave patterns 



Wave patterns (black and white photographs and color slides) were ob- 

 tained for existing conditions and the offshore breakwater plan for repre- 

 sentative test waves from the five selected test directions. 



Chapter 4 Tests and Results 



19 



