no seawalls present, GENESIS will not read from the input file SEAWL and will 

 place the seawall at -9999 distance units as a default; values in the SEAWL 

 file may be arbitrary in this case since the file will not be read. 



281. Line H.3: ISWBEG . ISWEND . As stated in the preceding two 

 paragraphs, if several seawall sections are present, they will be treated as a 

 single seawall but with the sections between them located far landward of the 

 shoreline. The grid cell numbers to be entered at this line correspond to the 

 beginning ISWBEG and ending ISWEND of the single, continuous seawall. The 

 two grid cell numbers are entered in ascending order. If ISWEND is set equal 

 to -1 at line H.3, internally GENESIS will set ISWEND = N , which is a 

 convenient default if all applications or variations for a project have a 

 seawall running from ISWBEG to N . 



I. Beach fills 



282. If more than one beach fill occurs, information must be entered in 

 order of occurrence of the fills. Fills may overlap in time and location, but 

 information must be entered in the same order at each request. GENESIS treats 

 the fill as having the same grain size and same berm height as the original 

 beach. 



283. GENESIS does not operate by direct use of fill volume but through 

 the total distance of shoreline advance after the fill and beach profile have 

 been molded to an equilibrium shape by wave action. (This distance must be 

 specified by the modeler at Line 1.8.) GENESIS places the fill by advancing 

 the shoreline position in equal amounts at each time step between the starting 

 and ending dates of the operation and within the cells defining the fill, as 

 specified at the START file line numbers described in the following para- 

 graphs. The fill is placed even if wave conditions are not sufficient to move 

 sand alongshore and the shoreline change computation is not carried out (for 

 example, during calm wave conditions). 



284. Because GENESIS places fill by advancing the shoreline in equal 

 daily amounts over the duration of the nourishment operation, a single fill 

 advances uniformly over its longshore extent. A nonuniform advance over a 

 given reach can be simulated by specifying several fills of different amounts 

 on different sections of a total reach but placed within the same period. 



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