successive runs for the two different run sequences, and the duration of 

 eacli experiment. During each run, test condition control data, including 

 Stillwater surface elevation and wave period, and independent variable 

 data, including wave reflection measurements, breaker and runup observa- 

 tions, and current data (in 1972) were collected. Profile surveys were 

 made after each run. Water temperature was monitored twice daily (morning 

 and evening). Less frequently, with the wave tanks drained, ripple forma- 

 tions were photographed, surface sand samples were collected, and additional 

 smaller grid surveys were made. The basin was drained slowly to minimize 

 erosion damage to the ripples, which could be caused by ground water seepage 

 or impoundment by ripples and bars. 



3. Records . 



Since various types of data were collected, an organized procedure for 

 recordkeeping was developed. The primary record was the laboratory note- 

 book in which a daily log of test activity was maintained. To ensure that 

 a complete, detailed account of all test events was obtained for later 

 reduction and analysis, other data collection forms were necessary. An 

 example and a brief description of the significant types of data collection 

 forms are given in Appendix A. Standardization in data collection was 

 achieved by either using regulation forms or designing new forms for spe- 

 cific types of data. 



4. Profile Construction . 



The sand beach was graded using the same procedure in each experiment 

 to minimize the possible effects of unequal compaction. The sand, when 

 shoveled into the tanks, was loosely packed and higher elevations than 

 desired were established for the initial grading. The basin was completely 

 filled and then drained, allowing the sand to compact before the slope was 

 regraded to the exact elevations desired. The basin was then filled to the 

 standard depth and after 24 hours the initial survey was made. The inter- 

 section of the SWL with the initial sand slope at the center wall was 

 established as the origin of the coordinate system (defined in Fig. 5) . 



5. Profile Protection . 



Every evening and during inclement weather, plywood covers were placed 

 over the subaerial part of the profile to prevent damage from wind or rain 

 (Fig. 4). A plastic sheet was placed over the plywood covers to prevent 

 water from dripping through the gaps between the covers. This practice also 

 allowed a run to be completed if it rained. When runs were not in progress, 

 a plywood sheet was lowered into the water (without disturbing the profile) 

 at the seaward end of the covers to prevent wind-generated waves from reach- 

 ing the beach. Copper sulfate was added to the water weekly to retard the 

 growth of algae, which can cement the sand bottom and retard sediment 

 motion. Leaves frequently fell into the test area, and daily cleaning of 

 the subaerial beach and water surface was necessary. 



16 



