step 1 





Step 2 





Step 3 





Step 4 





Step 5 



Do you have? 



Estimate of 



Q from 

 nearby site 



Go to section: 



Method 1 









III, 1 



Modify for 



local 

 conditions 









Historical changes 



Charts Surveys 

 Dredging reports 

 Aerial photos 



Height 

 Direction 



Height 



Collect 

 data? 



Method 2 









III, 2 



Analyze 

 changes in 

 nearshore zone 









Method 3 











III, 



3 



Equations 

 C8) to (12) 











Equation 

 (14) 



Step 1 



Step 



Figure 1. Selection guide to the four methods of 

 estimating longshore transport rate. 



I. Study historical records of the area to see if sediment 



transport patterns and accretion or erosion volumes can be determined. 

 Charts, surveys, dredging reports, beach nourishment reports, and 

 aerial photos are primary sources. If these records exist, go to 

 Section III, 2 and use method 2; if not, proceed to step 3. 



Step 3 . Study the wave data available for the area. If the data 

 include at least wave height and direction, go to Section III, 3 and 

 use method 3. If only wave height is available, go to step 4. If no 

 wave data are available, go to step 5. 



Step 4 . With only an estimate of the wave height, go to Section 

 III, 4 and use method 4. Remember that method 4 produces only an 

 estimate of the gross longshore transport rate. If more than a gross 

 estimate is needed, go to step 5. 



Step 5 . This situation is reached if no data are available for 

 estimating longshore transport rate. The only choice here is to 

 collect data if judged necessary after considering the importance 

 to, and budget of, the project. If some data are collected, return 

 to step 1. 



Method 1. 



The longshore transport rate at a given location can be estimated by using 

 a value for the transport at a nearby site modified for local conditions. Engi- 

 neering judgment is an important part of this method. The first step is to 



