handed directly to the keypuncher at the VIMS Computer Center for data 

 processing. 



2 . Surveyed Bench Marks . 



Three 0.5-inch (1.3 centimeters) galvanized iron pipes, 4 to 5 

 feet (1.2 to 1.5 meters) long, were driven approximately 3 to 4 feet 

 (0.9 to 1.2 meters) into the dune area at each of the 18 survey loca- 

 tions, except profile line 3 at Virginia Beach where the east face of 

 the concrete seawall was used in place of a pipe. 



Pipe 1, generally placed on the most seaward dune where there was 

 an unobstructed view of the profile line to the sea, was then used as 

 the reference point at each of the profile lines. Pipe 2 was usually 

 placed on the adjacent dune ridge landward to pipe 1. This pipe was 

 surveyed into various local landmarks (i.e., houses, power poles, and 

 other stakes) by magnetic bearing and distance at the beginning of 

 the study. Pipe 3 was placed near the edge of heavy dune vegetation, 

 or other area well back from the traveled section of dunes and beach, 

 and concealed from public view. The three pipes formed a straight 

 line oriented perpendicular, or nearly so, to the existing shoreline. 



All three pipes at each profile location were surveyed to third- 

 order accuracy by Freeman and Johnson, Engineers and Surveyors, of 

 Virginia Beach, Virginia, in April 1976 (App. G) . All elevations are 

 measured from the top of each pipe to MSL. The elevations for the most 

 seaward pipes range from 7.45 to 22.24 feet (2.27 to 6.78 meters) 

 above MSL. The distances from these pipes to the waterline range from 

 30 to 130 meters. Some distances have been shorter or longer due either 

 to storm high tides, or extreme low tides. 



3 . Wave Observers . 



As part of this study, volunteers were recruited to make daily 

 observations of wave data at one of the 10 observation sites. 

 The volunteer's estimates of the wave period, the breaker height, 

 the wave angle at the breaker, and the breaker type were recorded 

 on a wave observation report form made specifically for this study. 

 Wave period was measured using a stopwatch, from which the observer 

 read the time elapsed during the passage of 11 wave crests past a 

 fixed point. Breaker types were categorized as either spilling, 

 plunging, surging, spilling-plunging, or collapsing. Breaker 

 heights were estimated visually to the nearest one-half foot, and 

 the number recorded was the average of the highest one-third of 

 the breakers. The angle a breaker made with the shoreline was 

 measured to the nearest degree with a protractor furnished on the 

 back of the observation form. 



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