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locations. If the principal locations of dredging are moved inland, 

 dredged material disposal could become even more costly. These 

 circumstances could conceivably lead to new solutions that minimize the 

 total cost of shore protection, dredging, navigation, and water supply, 

 such as reducing channel depths by use of lightering and creation of 

 artificial shorelines and port islands with dredged material. 



Research Needs 



Both site -specific research and generic research are needed to work 

 both ends of the sedimentation question: the lack of sediment that 

 contributes to shoreline loss and the excess of sediment that impedes 

 navigation. 



For sedimentation purposes , exact rates of sea level rise are not 

 necessary. Approximate values will do for impacts evaluation. Local 

 subsidence rates, which are not very well defined, are important and should 

 be better defined. Better datum definition and water level measurements 

 are needed. 



Evaluation of sea level rise impacts should also address changes in 

 water and sediment supply, which may be changing as dramatically as sea 

 level. 



Demonstrations are needed of total cost minimization for all the 

 consequences mentioned in the last paragraph in the text discussion above. 

 This will involve modeling sediment, saltwater intrusion in rivers and 

 groundwater, shoreline response, and shipping. 



REFERENCE 



Beard, L.R. (1987). "General Considerations for Managing Floods and 



Droughts," Engineering Hydrology, American Society of Civil Engineers, 



New York. 



