inlets and bar channels; evaluation of factors 

 affecting rate of shoaling of bar channels and 

 salinity intrusion; study of tidal currents in inlets 

 and their relation to tidal heights and inlet 

 hydrography; and the development of an econom- 

 ical method of stabiUzing and maintaining author- 

 ized navigation channels through coastal inlets. 



-Design of coastal structures. Research is needed 

 to develop improved criteria for the design of 



fixed coastal structures such as jetties and jetty 

 channels, breakwaters for protecting harbor en- 

 trances, groins for protecting beaches, navigation 

 channels and chaimel training works in tidal 

 estuaries, and sand bypassing plants. The research 

 includes determination of wave forces and runup 

 on shore structures and the structural design 

 required to withstand the forces and the soil 

 mechanics and geology involved in their design. 



III-80 



