GROUND WATER--Release of OFR 94-533, "Documentation of AIR3D,an adaptation of the ground-water flow code MODFLOW to simulate three-dimensional air flow in the nsaturated zone" by Craig J. Joss and Arthur L. Baehr



In Reply Refer To:                       April 23, 1996
Mail Stop 411



OFFICE OF GROUND WATER TECHNICAL MEMORANDUM NO. 96.03

Subject:  GROUND WATER--Release of OFR 94-533, "Documentation of 
          AIR3D,an adaptation of the ground-water flow code 
          MODFLOW to simulate three-dimensional air flow in the 
          unsaturated zone" by Craig J. Joss and Arthur L. Baehr

The subject report describes AIR3D, a pair of computer programs 
that allow the MODFLOW ground-water flow model to be used to 
simulate three-dimensional air flow in the unsaturated zone.  
AIR3D is designed to simulate induced air flow for the purpose 
of vapor-extraction remediation.  It also can be used to 
simulate natural air flow in the unsaturated zone caused by 
atmospheric-pressure variation.  The method works by matching 
the coefficients of the air-flow equation to coefficients of the 
ground-water flow equation. One of the AIR3D programs uses 
pneumatic and geologic information to create input files for 
MODFLOW.  The second program takes the output from MODFLOW and 
converts it into dimensionally consistent air-flow output -- 
pressure, mass flow rates, and volumetric flow rates.  We 
recommend that this report be brought to the attention of 
technical and management personnel concerned with ground-water 
modeling studies.

To obtain a copy of the report, which includes the source code 
on diskette, contact Art Baehr in the New Jersey District 
(phone: 609-771-3978, electronic mail: abaehr).  The Hydrologic 
Analysis Software Support (HASS) Team will incorporate AIR3D in 
their software distribution system in the future.




                              William M. Alley
                              Chief, Office of Ground Water

Distribution:  A, B, FO, PO