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the tide in the bay is little affected by a rise in sea level, it is 

 expected that the inlet cross -sectional areas will adjust to the rising sea 

 levels and retain the original cross -sectional area. 



Increased sea level will lead to more frequent breaching of barrier 

 islands. The newly created inlets will affect the existing ones. 



Constructed Works 



Incorporate expected increase in sea level in the design of 

 structures. Many coastal structures are designed for storm conditions. 

 When restricting attention to the lifespan of a structure, isn't sea level 

 rise negligible with regard to the uncertainties in the level of storm 

 surges? Carry out sensitivity analysis. 



Research Needs 



Using the present techniques to analyze the stability of inlets, 

 evaluate the effect of sea level rise for a few typical inlets . Include 

 breaching of barrier islands. 



SECT. 9. UPRIVER SALTWATER PENETRATION 

 Estuarine Transport Processes/Salt Intrusion 



The upestuary transport of dissolved constituents, including salt, is 

 the result of complex interactions of residual currents and mixing. The 

 complexity of the processes in many cases defies our intuition. For 

 example, increasing the tidal range does not necessarily imply an increase 

 in salt penetration. Abraham et al. (1986) showed that in one of the two 

 branches of the Nieuwe Waterway (Rotterdam) maximum salt intrusion occurred 

 during neap tides and in the other during average tide conditions. 



Residual currents and mixing processes in an estuary are determined by 

 the external forcings 



- wind, 



- ocean tide off the estuary mouth, and 



- density gradients in the estuary 

 and by the 



- bathymetry of the basin. 



