Input Data 



56. Identification and evaluation of alternative solutions can begin 

 once a problem statement has been formulated. Development of a solution and 

 use of GENESIS are based on physical data and quantification of the processes 

 involved. The necessity of satisfying data requirements prior to application 

 of GENESIS systemizes the procedure of data collection and analysis and is a 

 benefit to all aspects of the project. 



57. Various types of data are involved in project evaluation: legal, 

 financial, cultural, environmental, and physical. Here only physical data are 

 considered. Physical data are required for two purposes: 



a. To obtain background information for making a general and 

 integrated assessment of coastal processes at the site and of 

 the geographic region. 



b. To calibrate, verify, and make predictions with GENESIS. 

 Complete guidance covering item a cannot be given, as each project will have 

 unique characteristics. Coastal engineering and geological experience must be 

 relied upon to determine special factors, physical and environmental, which 

 may affect project design and performance. The present section deals with 

 item b, data necessary to run GENESIS. However, since the data sets needed to 

 run GENESIS encompass many aspects of coastal processes, clues pointing toward 

 site -specific data requirements can be expected. 



58. The first technical step in a modeling task is to establish a 

 shoreline coordinate system. The regional trend of the coast is determined 

 from a wide-scale chart, whereas the trend of the local shoreline is deter- 

 mined from a small-scale chart. The regional trend is used to identify the 

 orientation of offshore contours for wave refraction modeling, whereas 

 shoreline positions, structure configurations, and other project- specific 

 information are referenced to the small-scale chart. 



59. A decision is made on the trend of the shoreline, and a longshore 

 (x) axis is drawn parallel to the trend. A shore -normal (y) axis is then 

 drawn pointing offshore to create a right-hand system, as shown in Figure 5. 

 Based on the availability and quality of data, extent of the modeled area, 

 detail desired, and the level of effort, the grid spacing is specified. 

 Typical longshore spacing is 25, 50, or 100 m if working in the metric system, 



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