in model input occur frequently during model testing and verification, and the 

 data files serve as a record of the run. The interface method is also 

 compatible with a batch mode of computer operation, whereby jobs are submitted 

 for execution (launched) in an automated manner according to rules of the 

 particular operating system. 



Cautions 



13. Numerical modeling of shoreline change is a specialized and highly 

 technical area of coastal engineering. Firm understanding of coastal hydro- 

 dynamic and sediment transport processes is a prerequisite to operation of a 

 shoreline change simulation model. Incautious use of models and incorrect 

 interpretation of results can lead to costly mistakes. Sophisticated models 

 such as GENESIS should be operated by trained individuals familiar with the 

 coast, and results should be examined in light of the observed behavior of the 

 waves, currents, sediment movement, and beach change that occur along that 

 coast. To operate GENESIS properly, careful reading of this report is 

 required. 



Scope of This Report 



14. This report has two functions. First, it is an introductory 

 technical reference to GENESIS. The technical material covers the internal 

 working of GENESIS and is intended to increase understanding of the assump- 

 tions on which the modeling system is based. Discussion of numerical models 

 of beach change in general and project planning in association with GENESIS 

 are given in Parts II and III, respectively. Planners and coastal managers 

 should read Parts I -IV, as these chapters provide the methodology for use of 

 the modeling system, a background on shoreline change and other coastal 

 processes simulation models, and discussion of the limitations and capabil- 

 ities of GENESIS. Hands-on users of GENESIS should study the entire report, 

 especially technical aspects presented in Parts V and VI , whereas those who 

 will not operate GENESIS but only interact with modelers may omit this 

 material. Because of the nature of addressing the needs of both planners and 



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