New Recharge Options for MODFLOW-USG Transport

Do you have to refine the recharge options in your MODFLOW-USG Transport model in the Groundwater Modeling System (GMS)? With GMS 10.8, we’ve added two options to the MODFLOW-USG Transport Recharge Package. Concentrations (CONC) option and Use Seep Elevation (SEEPELEV) option have now been added as options to the main dialog. This makes it easier to add the data required when concentrations and/or seepage elevations are required for certain species. These additions can improve the accuracy and applicability of groundwater models, particularly in complex and variable hydrological settings.

Adding the Concentrations (CONC) feature to the Recharge (RCH) package in MODFLOW-USG Transport allows you to account for the spatial and temporal variations in the concentration of contaminants or solutes in recharge water.

The Use Seep Elevation (SEEPELEV) feature enables you to consider the elevation of seepage faces in your simulations. This is particularly important in areas with complex topography and variable groundwater-surface water interactions.

In order to use these options:

1. Go to MODFLOW | Global Options.
2. In MODFLOW Global/Basic Package, select Packages.
3. Make sure “RCH1” has been selected as one of the packages.
4. Then, access the RCH package options using the RCH - Recharge Package command in MODFLOW | Optional Packages menu. You can also reach the options by double-clicking on the RCH package in the Project Explorer.
5. In the MODFLOW Recharge Package dialog, look for “Concentrations (CONC)” and “Use Seep Elevation (SEEPELEV)”. They will appear below the “Recharge option (NRCHOP)” drop down.
6. Select one or both of them, depending on your model’s needs.
7. For the seep elevation, you can manually enter or import the appropriate data.

Note: These options are only a part of USG Transport and are not available in other versions of MODFLOW..

With these two options now available in MODFLOW-USG Transport, better refinement in your groundwater models is now possible. Head on over to GMS 10.8 to try out the Concentrations (CONC) and Use Seep Elevation (SEEPELEV) options in your MODFLOW-USG Transport projects today!