period-direction bands to limit the number of distinct wave transformation 

 calculations that must be made. This topic is discussed further in Part V. 



Table 2 

 Data Required for Shoreline Change Modeling 



Type of Data 

 Shoreline position 



Offshore waves 



Beach profiles and 

 offshore bathymetry 



Comments 



Shoreline position at regularly spaced intervals 

 alongshore by which the historic trend of beach 

 change can be determined. 



Time series or, at a minimum, statistical summaries of 

 offshore wave height, period, and direction. 



Profiles to determine the average shape of the 

 beach. Bathymetry for transforming offshore 

 wave characteristics to values in the nearshore . 



Structures and 



other engineering 

 activities 



Regional transport 



Regional geology 



Water level 

 Extreme events 



Other 



Location, configuration, and construction 

 schedule of engineering structures (groins, 

 jetties, detached breakwaters, harbor and port break- 

 waters, seawalls, etc.). Structure porosity, reflec- 

 tion, and transmission. Location, volume, and 

 schedule of beach fills, dredging, and sand mining. 

 Sand bypassing rates around jetties and breakwaters. 



Identification of littoral cells and transport paths. 

 Sediment budget. Locations of inlets. Wind-blown 

 sand transport. 



Sources and sinks of sediment (river discharges, cliff 

 erosion, submarine canyons, etc.). Sedimentary 

 structure. Grain size distribution (native and of 

 beach fill). Regional trends in shoreline movement. 

 Subsidence. Sea level change. 



Tidal range . Tidal and other datums . 



Large storms (waves, surge, failure of structures, 

 etc.). Inlet opening or closing. Earthquakes. 



Wave shadowing by large land masses. Strong coastal 

 currents. Ice. Water runoff. 



36 



