VI-155 



models is the need to know, understand, and quantify every one of 

 the factors of the system being modeled. In the absence of any 

 portion of this kind of information, assumptions must be made. 

 The more complicated a system, the greater the area of ignorance, 

 the more assumptions must be made, and the less confidence 

 can be placed in the results. To date, effective mathematical 

 modeling activities have been applied for some of the more impor- 

 tant water quality parameters, such as dissolved oxygen, in some 

 of the simpler estuarine systems. The research need here is to 

 overcome all of the difficulties and satisfy the drawbacks just 

 stated. Obviously, this approach should be most valuable if and 

 when perfected. 



SUMMARY 



A. Hydraulics 



1. Develop complete understanding of the water dynamics of 

 the estuary, including details of tidal and current 

 regimes, evaluations of the effects of river flows, rates 

 of water exchange, and characteristics of flushing. 



2. Determine the source, activity, and fate of both conser- 

 vative (e.g., salt) and non-conservative (e.g., pesticides, 

 nutrients) materials in the estuary. 



3. Classify estuaries according to flushing characteristics 

 in order to enhance our predictive capability for waste 



