- Download WHAFIS, Version 4.0
- Coastal Flood Hazard Technical Resources
- Subscribe to Receive WHAFIS News and Information
Wave Height Analysis for Flood Insurance Studies (WHAFIS), Version 4.0, is a DOS-based program that uses representative transects to compute wave crest elevations in a given study area. Transects are selected by considering major topographic, vegetative, and cultural features. WHAFIS uses this and other input information to compute an appropriate depth-limited wave height at the seaward end of each transect. Review Section D.2.7, Overland Wave Propagation, in the Atlantic Ocean and Gulf of Mexico Coastal Guidelines Update for more information about the program.
FEMA's Overland Wave Propagation program WHAFIS (previously Version 3.0) has been revised for two major reasons:
As part of the Pacific Coast Guidelines development, it was determined that WHAFIS should be generalized for Pacific applications to permit the use of arbitrary wind speeds. WHAFIS 3.0 incorporates default wind speeds that are representative of 100-year hurricane conditions on the Atlantic and Gulf coasts, but which are not appropriate for most Pacific coast applications. The default WHAFIS 3.0 wind speeds are not accessible to the user, but are hardwired into the program code. Consequently, a generalized version of WHAFIS for Pacific applications was developed, called PWHAFIS (Pacific WHAFIS), allowing the user to override the default speeds.
As part of the 0.2-percent-annual-chance coastal flood guidelines development for the Atlantic Ocean and Gulf of Mexico coasts, it was determined that WHAFIS should be revised to incorporate default wind speeds appropriate for 0.2-percent-annual-chance conditions in addition to the 1.0-percent-annual-chance wind speeds used in WHAFIS3.
WHAFIS 4.0 is an updated version incorporating both of these changes, as well as certain other refinements, bug-fixes, and improved input (two types of comment cards) and output documentation.
WHAFIS 4.0 has been designed so that by default it is transparently compatible with all old analyses that were made using WHAFIS3. That is, any WHAFIS3 input file should run under WHAFIS 4.0 without any modification, and should produce identical numerical output.
For more information on how to use WHAFIS 4.0 with its new non-default modes and additional features please see the Supplementary WHAFIS Documentation.
The WHAFIS program is provided in a Zip archive below along with software installation instructions. For more information concerning how to use the program, please view the Readme file. If you need additional information about how to obtain and use WinZip, please see the "Download Plug-in" section at the end of the page.
Download WHAFIS, Version 4.0
- Extract the Zip file to a local directory (e.g., C:\temp) on your computer's hard drive.
- Open the Zip file and extract the program files to a local directory on your hard drive. (e.g., C:\WHAFIS)
(NOTE: all of the WHAFIS files must be in the same directory for the program to function properly on your system.)
- View the WHAFIS, Version 4.0, Readme file and set up the necessary input and output files for the program. After this step is complete, you are ready to run WHAFIS to calculate wave heights and determine hazard zones.
Go to the DOS prompt and navigate to the directory where the WHAFIS files were saved in Step 2.
- Run WHAFIS by typing the following at the DOS prompt:
x:\DirectoryName\Whafis3 Filename.in Filename.out
x = the drive where the WHAFIS files are located;
DirectoryName = the name of the directory where the WHAFIS files are located; and
Whafis3 = the command to start the WHAFIS program.
Filename.in = the name of the WHAFIS input file; and
Filename.out = the name of the WHAFIS output file.
Coastal Flood Hazard Technical Resources
Subscribe to Receive WHAFIS News and Information
Please register to receive e-mail updates on FEMA Flood Hazard Mapping activities, including the latest on WHAFIS.