Thursday, May 12, 2011

MODFLOW-NWT Documentation Released

The documentation for the new MODFLOW-NWT code is now on the USGS web site (see link below). This new version of MODFLOW offers a Newton formulation for nonlinear problems, especially those involving drying and rewetting of cells. It is a special version of MODFLOW2005 that has a new solver (NWT) and a new version of the Layer Property Flow (LPF) Package called the Upstream Weighting Package (UPW). The format of the UPW Package is virtually identical to LPF so the transition to MODFLOW-NWT is relatively simple. It's really just a matter of substituting a new solver file.

MODFLOW-NWT handles dry cells in a manner similar to MODFLOW-Surfact's pseudo soil relations. So if you do not want to spend the money for MODFLOW-Surfact, then MODFLOW-NWT is a viable alternative. The downside is that MODFLOW-NWT can be slower than MODFLOW-Surfact. I have confirmed this with some test problems and real models. But it works!

The source code should be available in a few days. As soon as the source code appears on the USGS web site we will activate this feature in Groundwater Vistas Version 6. I will make another post when that happens.

Link to MODFLOW-NWT manual:


Post a Comment

<< Home