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support this recommendation, as such a model is needed, even in the absence 

 of sea level rise. 



SECT. 7. SHORELINE RESPONSE MODELING 



The primary purpose of this section is to discuss the relationship of 

 shoreline recession to sea level rise. The well-known Bruun rule and its 

 progeny are discussed, as are their shortcomings, such as the requirement 

 of offshore sediment transport. 



Of utmost importance is the determination of the amount of shoreline 

 recession due to sea level rise. Part of the recession is due to the 

 on/offshore transport of shoreline material. The section points out the 

 importance of alongshore transport as well, with the example of tidal 

 inlets in starving downdrift beaches, leading to shoreline recession, which 

 would occur in the absence of sea level rise. 



Clearly we need to document the influence of cross -shore transport 

 under rising sea level conditions. Dean (1987) has indicated that there 

 are problems with the Bruun model. If offshore sources do exist, they may 

 mitigate some of the Bruun rule shoreline recession. 



Research Needs 



Determine the cross -shore sediment transport paths and the shoreline 

 recession due to sea level rise. Note that this is an integral part of the 

 Sect. 6 recommendation for the development of a general coastal response 

 model. 



REFERENCES 



Dean, R.G. (1987). "Additional sediment input to the nearshore region, 



Shore and Beach 55(3-4), 76-81. 

 National Research Council (1987). Responding to Changes in Sea Level: 



Engineering Implications, National Academy Press, Washington, D.C. 



