SHORC 



316. The output file SHORC.DAT holds the "final" calculated position of 

 the shoreline, i.e., the position of the shoreline at the last time step 

 (SIMDATE at Line A. 7 in the START file). The format of SHORC.DAT is such that 

 the file can be copied to an input SHORL file holding the "initial" shoreline 

 corresponding to the next stage of a simulation. This file is useful if the 

 configurations of structures change over the course of the simulation period, 

 as described Part V. The objective fitting criterion, quantified by the para- 

 meter Y diff , is determined by comparing the calculated final shoreline 

 location held in SHORC.DAT with the measured final shoreline location held in 

 SHORM.DAT. The variable Y diff expresses the mean difference in location 

 between the calculated final shoreline and the corresponding measured one. 



Error and Warning Messages 



317 . After all needed input files are prepared and available to be 

 called by GENESIS, the program can be run. At the beginning of use of the 

 model on a project, it is not uncommon and should not be unexpected to have 

 data mismatch errors, particularly in the START file. GENESIS provides a 

 number of error and warning messages that give the user recovery information 

 for the more common mistakes and notification of potentially undesirable 

 conditions encountered during a simulation. These messages are printed to 

 screen and to the output file SETUP. Error and warning messages and suggested 

 recovery procedures are given in Appendix C. 



318. One strategy that has been found useful for reducing errors is to 

 introduce project complexity in the START file in stages, testing (running) 

 the model for a few time steps at each stage. For example, if the project has 

 several structures and beach fills, the START file would first be constructed 

 with only the boundary conditions and tested. Next, perhaps only nondiffract- 

 ing groins would be placed on the internal grid, if there are such structures. 

 Then, diffracting structures would be introduced. Finally, after successful 

 testing at each stage, the beach fills would be placed in the START file. In 

 this way, errors can be more easily isolated. 



136 



