APPENDIX C: ERROR AND WARNING MESSAGES AND RECOVERY PROCEDURES 



1. This appendix contains a list of error and warning messages that are 

 presently incorporated in the Generalized Model for Simulating Shoreline 

 Change (GENESIS). The error- trapping capability of new versions of GENESIS is 

 expected to be an active area of improvement in the modeling system, and an 

 expanded list of enhancements will be provided with new versions. As describ- 

 ed in the main text of this report, error messages indicate a condition that 

 will stop operation of the modeling system, whereas warning messages indicate 

 a potentially undesirable condition, but the calculation is allowed to 

 proceed. 



2. Messages are given in alphabetical order in bold capital letters, 

 followed by an explanation and suggested error -recovery procedure. The 

 material is repetitive to allow the user to read without cross-reference. 



Error Messages 



3. ERROR. BAD BALANCE IN WAVE INPUT PARAMETERS CAUSING DLTZ TO BE 

 NEGATIVE. The depth of longshore sand transport (DLTZ is called "D LTo " in 

 the main text) is proportional to the wave height with a correction for the 

 wave steepness. For actually occurring waves, this correction term is small, 

 but in situations for which the modeler fabricates a wave climate, the 

 correction term can inadvertently become unphysically large. This error 

 message will appear if the depth of longshore sand transport becomes negative 

 and is remedied by changing the wave height and/or period in the WAVES file to 

 represent physically reasonable waves. 



4. ERROR. BEACH FILL IS OUTSIDE CALCULATION GRID. GENESIS has the 

 option of performing simulations over a portion of the beach through specifi- 

 cation of grid cell numbers other than 1 and N+l where the simulation 

 starts and ends. These numbers are entered on Line A. 4 in the START file. To 

 facilitate use of the model, the coordinates of beach fills, as specified on 

 Lines 1.6 and 1.7, and structures are always given in the total coordinate 

 system. In this way the modeler does not have to change the coordinates of 

 operations as he or she targets one portion of the beach or another to be 



CI 



