Many techniques used during this study are outgrowths of studies 

 conducted on Lake Michigan during 1969 and 1970 by Fox and Davis (1970). 

 Earlier work on time-series studies or detailed beach process studies 

 was carried out by Harrison and Krumbein (1964), Sonu and Russell (1966), 

 Sonu, McCloy, and McArthur (1966), Dolan, Ferm, and McArthur (1968), and 

 Harrison, et al. (1968). The techniques and methods of data analysis 

 reported in these earlier studies proved valuable in the development of 

 this program. 



Coastal processes of Plum Island and adjacent estuaries have been 

 discussed in detail by several members of the Coastal Research Division, 

 University of South Carolina (formerly the Coastal Research Group, 

 University of Massachusetts), including McCormick (1968), DaBoll (1969), 

 Coastal Research Group (1969), Hartwell (1970), and Anan (1971). 



II. FIELD METHODS 



Wave conditions, longshore currents, ground water elevations, meteor- 

 ological parameters, and tidal elevations were measured bihourly for 6 

 weeks in July and August 1971 (summer period) and for 4 weeks in January 

 1972 (winter period) <, Meteorological parameters measured included baro- 

 metric pressure, air and water temperature, windspeed and direction, sky 

 conditions, and precipitation. Tide readings were taken hourly using a 

 series of 250-centimeter stakes located about 20 meters apart and extend- 

 ing from the base of the dune scarp seaward to a point beyond the seaward 

 edge of the low tide terrace. Ground water elevation was measured by a 

 1.5-inch pipe driven 5 meters into the incipient berm. Wave height and 

 breaker depth were measured at the point of the breaking waves. Long- 

 shore currents were measured immediately landward of the breaker zone. 



1. Wave Conditions . 



Wave data collected consisted of bihourly measurements of breaker 

 height, breaker depth, wave period, breaker type, and breaker angle. 

 Values for wave steepness and breaker power were calculated from 

 measured wave parameters. 



The mean breaker power, expressed in kilograms per square second per 

 meter of crest width, was calculated from: 



— 8 pgH 3 / 2 h 3 / 2 

 Pbn 



3V3 T 



where 



Pb = the mean breaker power; 



pg = the specific weight of saltwater; 



H = the mean breaker height; 



h = the breaker depth ; and 



T = the mean wave period. 



This estimate of breaker power is for a solitary wave and is a summation 

 of the potential and kinetic energies of the wave (Ippen, 1966). 



13 



