MODPATH-NWT and MODPATH6 models used to compare a new general simulation model approach with a conventional inset model approach for groundwater residence time in glacial aquifers

This groundwater-flow model archive/data release contains the model input and output files for 1) edited versions of four of the five NAWQA steady- state, inset MODFLOW-NWT models of regional model of Lake Michigan Basin (https://doi.org/10.3133/sir20185038) and 2) general models simulating the same four basins as the four inset models. Two HUC8 basins in the lower peninsula of Michigan (Kalamazoo (KALA) and Boardman-Charlevoix (BOARD) basins) and two HUC8 basins in Wisconsin (Upper Fox (UFOX) and Manitowoc-Sheboygan (MANI) basins) are represented in the inset and genera-simulation models. The inset models are designed to serve as a training area for metamodels to estimate groundwater age in glacial wells. The construction and details of the original four inset models are outlined in the U.S. Geological Survey Scientific Investigations Report 2018-5038 (https://doi.org/10.3133/sir20185038), and the construction and details of the general models are outlined in the Water Resources Research journal article (https://doi.org/10.1029/2017WR021531). The original four inset models are archived in the data release at https://doi.org/10.5066/F76D5R5V. Groundwater withdrawals from wells in the original four inset models were removed in the inset models in this archive because the general models did not have wells and to be able to compare the results from the two types of models in the archive. The boundary conditions of these “pre-development” versions of the inset models were changed from constant-head boundaries (reflecting 2005 conditions) to no-flow boundaries. The general-simulation models apply an innovative modeling approach that allows for rapid,automated construction and calibration of models at a scale appropriate to the problem at hand (https://doi.org/10.3133/sir20215142). Results from the four general models in this archive were compared to results from the edited versions of the four inset models to evaluate the degree to which the general models reproduce behavior simulated by the inset models that use conventional flow modeling techniques. The underlying directories contain all the input and output files for the MODFLOW-NWT simulations and MODPATH particle tracking analysis for the edited versions of four inset models, and the four general models simulating the same four basins as the inset models described in the USGS Scientific Investigations Report (https://doi.org/10.3133sir20215142). The MODFLOW-NWT (v 1.0.9) and MODPATH 6 (version 6.0.1) executables and source codes, various ancillary python scripts written for this project, and model geospatial data are also included in the archive. Descriptions of the data in each subdirectory are provided to facilitate understanding of this this model archive. File descriptions are provided for select input and output files to provide additional information that may be of use for understanding this this model archive.