Stu(^ of Effects of Tidal Fluctuations on Wave Produced Beach 

 Profiles - The purpose of this laboratory study is to determine 

 the effect of introducing tidal fluctuations during the period the beach 

 is being formed. Eight tests were scheduled to adequately cover tiie 

 necessary tidal ranges and cycle frequencies o Due to other projects 

 of a higher priority which have developed demanding the use of the 85-foot 

 wave tarJcj, this study has been temporarily inactive since J4-IO-52. Prior 

 to this date^ two tests were completed but their significsjice cannot be 

 adequately evaluated until the remaining tests are completed. 



Study of Quantity of Sand in Suspension in Coastal Waters (in 

 two parts) 



Part 1, Laboratory development of a suspended sediment s ampler 

 for use in studies of sand transport by wave action - 



A pump type suspended sediment sampler was decided to be the 

 best approach in this study. The method was tested by utilizing a uni- 

 directional circulating system in which various concentrations of material 

 in suspension could be created. Samples were piimped from various points 

 in the test section by positioning the intake nozzle perpendicular to the 

 flow and these samples compared with samples taken at tlie same points 

 where the intake nozzle was oriented into the flow, with the intake nozzle 

 velocity adjusted to equal the flume velocity. The laboratory tests and 

 observations indicate that a pump -type sampler could be adapted to the 

 study of suspended material moveiaent in wave action. The report on this 

 phase of study has been completed and is under review for possible publica- 

 tion » 



Part 2. Field investigation of suspended sediment in surf zone 

 at Mission Bay, California - 



Based on laboratory tests , a pump type suspended sediment sampler 

 was constructed for field use. Basic ally ^ the sampler gathered a sediment 

 sample by pujnping from a selected point a quantity of sediment-laden water 

 through a filter which removed the sediment and discharged the water back 

 into the ocean| the amount of water pumped was measured by a meter connected 

 in series with the filter. Saxaples were taken off Crystal Pier, Mission 

 Bay, California. Although a limited range of wave conditions existed at the 

 time of sampling^ the average of the results indicates a fairly definite 

 correlation between concentration, water depths and wave heights. The 

 report on this field investigation has been completed and is under review 

 by the staff. 



Correlation of Effectiveness of South Lake Worth (Florida) 

 Inlet By-passing Plant with Rate of Drift Reaching Plant - Daily 

 measurements on winds, waves, littoral currents near the surf zone, and the 

 amount of material pumped at the by-passing plant were taken continuously 

 for a three month period (3/6/^2 - 6/6/52). The field data on this study 

 are being analyzed and a report is in preparation, 



31 



