In summary, it is vital that the user of wave data be aware of how wave 

 statistics have been calculated and thoroughly understand the limitations and 

 strengths of the computational methods that were employed. 



Display of wave data and statistics 



In order to manage the tremendous amount of data that are typically 

 acquired in a field experiment, perform quality control, and interpret the 

 results, wave data should be analyzed as soon as possible. In addition, there 

 is often an urgent need to examine the raw data to ascertain whether the gages 

 can be redeployed or must be repaired. 



Figures 30 and 32 are examples of pressure plotted against time. The 

 value of this form of display for quality control purposes has been 

 demonstrated, but these plots are of limited value in revealing information 

 about the overall nature of the wave climate in the study area. 



In order to review the data from an extended deployment, the summary 

 statistics must be tabulated or plotted. Figure 35 is an example of tabulated 

 directional wave data from a Florida project site. These same data are 

 graphically displayed in Figure 36. The upper plot shows H m0 wave height, 

 the center peak period, and the lower peak direction. Although other statistics 

 could have been plotted on the same page, there is a danger of making a 

 display too confusing. The advantage of the tabulation is that values from 

 individual wave bursts can be examined. The disadvantage is that it is 

 difficult to detect overall trends, especially if the records extend over many 

 months. As data collection and processing procedures improve, and as more 

 and more data are acquired at field projects, it will be increasingly difficult to 

 display the results in a useful and flexible format that does not overwhelm the 

 end user but yet also does not oversimplify the situation. 



Applications of wave data 



One important use of wave climate data in coastal engineering is in the 

 construction of wave refraction diagrams. These demonstrate how nearshore 

 bathymetry influences the direction of waves approaching the shoreline. This 

 information can be used to estimate mass transport and longshore transport of 

 sediment, which, in turn, can be used to predict morphologic changes under 

 both natural and structurally influenced coasts. Wave refraction analyses can 

 also be used for hypothetical scenarios, such as predicting the effects on 

 incident waves of dredging an offshore shoal or dumping dredged materials 

 offshore. 



Chapter 5 Analysis and Interpretation of Coastal Data 



89 



