ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
A previously-developed groundwater model of the Suwannee River Basin was modified and calibrated to represent transient conditions. A simulation of recent conditions was developed for the 372-month period 1970-2000, and was compared with a simulation of future conditions for a similar-length period 2039-2069, which uses downscaled GCM (Global Climate Model) data. The MODFLOW groundwater-simulation code was used in both of these simulations, and two different MODFLOW boundary condition “packages” (River and Streamflow Routing Packages) were used to represent interactions between surface-water and groundwater features. The parameters for the simulation of future conditions were developed from dynamically downscaled precipitation and evapotranspiration data generated by the Community Climate System Model.

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
A three dimensional groundwater flow model (MODFLOW-NWT) was developed to examine the effects of changes to engineering controls and Lake Michigan surface water levels on the distribution of ponded water near Long Lake in Indiana Dunes National Lakeshore, near Gary, Indiana. The steady state model was calibrated to relatively low groundwater level condition of October 2002 and a relatively high groundwater level condition of March 2011. Scenario models were generated that examined the effects of (1) removing the beaver dams in US-12 ditch, (2) discontinuing seepage of water from the filtration pond east of East Long Lake, (3) discontinuing discharge from US-12 ditch to the Gary Sanitary District sewer system, (4) decreasing discharge from US-12 ditch to the Gary Sanitary District sewer system, (5) connecting East Long Lake and West Long Lake, (6) deepening County Line Road ditch, and (7) raising and lowering the water level of Lake Michigan. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://pubs.usgs.gov/sir/2013/5003/).

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
A three-dimensional, groundwater flow model was developed with the numerical code MODFLOW-NWT to represent changes in groundwater pumping and aquifer recharge in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York to North Carolina. The model was constructed using existing hydrogeologic and geospatial information to represent the aquifer system geometry, boundaries, and hydraulic properties of the 19 separate regional aquifers and confining units within the aquifer system. The model was calibrated using an inverse modeling parameter-estimation (PEST) technique to conditions from 1986 to 2008, the period for which data are most complete and reliable. The simulation period for this analysis spanned from predevelopment to future conditions, from 1900 to 2058. The model was used to advance the understanding of groundwater budgets and components including recharge, discharge, and aquifer storage for the entire system and for each of the statewide systems; compute historical and recent system response and project future system response to development at a scale relevant to basinwide water-management decisions; and evaluate options for hydrologic monitoring of system changes. The report ‘Documentation of a groundwater flow model developed to assess groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina: U.S. Geological Survey Scientific Investigations Report 2016–5076' (https://dx.doi.org/10.3133/sir20165076) documents the model design and calibration, as well as several simulations to test model construction assumptions. The report 'Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina: U.S. Geological Survey Professional Paper 1829' (https://dx.doi.org/10.3133/pp1829) documents water-availability simulations and the resulting analysis and discussion. This USGS data release contains all of the input and output files for the simulations described in the associated reports (https://dx.doi.org/10.3133/sir20165076) and (https://dx.doi.org/10.3133/pp1829). This data release also includes (1) MODFLOW-NWT source code, (2) the PEST files and source code used for model calibration, and (3) the ZONEBUDGET input files and source code used for the groundwater availability analysis.

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
This data release contains three groundwater-flow models of northeastern Wisconsin, USA, that were developed with differing levels of complexity to provide a framework for subsequent evaluations of the effects of process-based model complexity on estimates of groundwater age distributions for withdrawal wells and streams. Preliminary assessments, which focused on the effects of model complexity on simulated water levels in the glacial aquifer system, illustrate that simulation of vertical gradients using multiple model layers improves simulated heads more in relatively low-permeability units than in high-permeability units. Moreover, simulation of heterogeneous hydraulic conductivity fields in both coarse-grained and some fine-grained glacial materials produced an even larger improvement in simulated water levels in the glacial aquifer system compared with simulation of uniform hydraulic conductivity within zones. Future application of the models using simulated particle tracking is anticipated to evaluate whether these model design considerations are similarly important for understanding groundwater age distributions. This work was performed as part of the National Water Quality Assessment (NAWQA) Project's groundwater Mapping and Modeling work plan to evaluate effects of differing levels of model complexity on simulated results. The models were calibrated to approximately the 1970-2012 period, and used to simulate steady-state conditions. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://dx.doi.org/10.3133/sir20175010). This data release also includes a postprocessing python script and associated input data files for creating shapefiles used to produce maps of head and flux residuals and comparisons of these residuals (figures 12, 13, and 19 in the report).

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
A new groundwater flow model was created for Dane County, Wisconsin, to replace an earlier model developed in the 1990s by the Wisconsin Geological and Natural History Survey (WGNHS) and the U.S. Geological Survey (USGS). This modeling study was conducted cooperatively by the WGNHS, the Capital Area Regional Planning Commission, and the USGS. Although the overall conceptual model of the groundwater system remains largely unchanged, the incorporation of newly acquired, high-quality datasets, recent research findings, and improved modeling and calibration techniques have led to the development of a much more detailed and sophisticated model representation of the groundwater system. The new model is three-dimensional and transient, and conceptualizes the county’s hydrogeology as a 12-layer system including all major unlithified and bedrock hydrostratigraphic units and two high-conductivity horizontal fracture zones.

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
A three-dimensional groundwater flow model was developed to characterize groundwater resources and the interaction of groundwater with streams and other hydrologic features in the Northern High Plains aquifer. The Northern High Plains aquifer is generally unconfined; most of the water withdrawn from the aquifer is used for irrigation. A modified version of a previously published soil-water-balance (SWB) model estimates recharge using climatic, soils, land cover data, in addition to data for groundwater withdrawals for irrigation. The SWB output was adjusted in areas where surface water is used for irrigation. The groundwater flow model results were calibrated using parameter estimation to measured groundwater levels and estimated stream base flows. The model was designed as a tool for regional evaluations of groundwater resources and of groundwater interactions with streams and other hydrologic features resulting from current or forecasted conditions. This USGS data release contains all of the input and output files for the model described in the associated model documentation report (https://dx.doi.org/10.3133/sir20165153). This data release also includes (1) MODFLOW-NWT (version 1.0.9) source code, and (2) SWB source code in two formats.

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
This Data Release has 18 different groundwater flow simulation applications for the Woodville Karst Plain area near Tallahassee Florida with three variations of distributed parameter model approach. The site model files provided include both calibrated and uncalibrated simulations of various steady-state and transient hydrologic conditions. Simulations were accomplished with equivalent porous media models that allow laminar flow only (MODFLOW) or laminar and non-laminar flow in a model layer (MODFLOW-CFP mode 2) and hybrid model simulations (MODFLOW-CFP mode 1 one-dimensional pipe network linked to equivalent porous media model). The test examples of the application of equivalent porous media model (the sponge) with and without turbulence and a hybrid model (sponge with pipes) to the Woodville Karst Plain near Tallahassee, Florida, indicated that for annual, monthly, or seasonal average hydrologic conditions, all methods met calibration criteria (matched observed water levels and average flow). Thus, the increased effort, such as the collection of data on conduit location and the computational time of a hybrid model, is not necessary for simulation of average hydrologic conditions (simulation of non-laminar flow was not critical). However, simulation of a large storm event in the Woodville Karst Plain with daily stress periods (52-day period beginning August 13, 2008) indicated that turbulence is important for matching daily springflow hydrographs and models calibrated to average conditions did not match daily storm spring hydrographs. All models were developed from an equivalent porous media model for the area calibrated by J. Hal Davis, USGS, Tallahasee Florida Office that is documented in Davis, J.H., Katz, B.G., and Griffin, D.W., 2010, Nitrate-N movement in groundwater from the land application of treated municipal wastewater and other sources in the Wakulla Springs springshed, Leon and Wakulla Counties, Florida, 1966–2018: U.S. Geological Survey Scientific Investigations Report 2010–5099, 90 p. (https://pubs.usgs.gov/sir/2010/5099/). The hybrid model was developed by Josue J. Gallegos and documented in Gallegos, J.J., Hu, B.X., and Davis, Hal, 2013, Simulating flow in karst aquifers at laboratory and sub-regional scales using MODFLOW-CFP: Hydrogeology Journal, v. 21, no. 8, p. 1749–1760.

ABSTRACT:

***USGS TEST ENTRY*** Contact Todd Koenig at tkoenig@usgs.gov for more information.
An existing three-dimensional model (MODFLOW-2000) by Petkewich and Campbell was modified to simulate potential changes in groundwater-level conditions caused by withdrawals from a proposed well in the Middendorf aquifer near Monocks, South Carolina. A single well was added to the existing model in the cell at row 67 and column 119 in layer 7 (the Middendorf aquifer). Two scenarios were created by modifying the Base Case simulation which is documented in the model documentation report (https://pubs.usgs.gov/sir/2009/5185/) and data release (https://dx.doi.org/10.5066/F7JW8C1K). The proposed well was pumped at 0.5 million gallons per day for the 'proposed well 1.5 MGD' scenario and 1.5 million gallons per day for the 'proposed well 1.5 MGD' scenario. This was the only change made to the model for this data release. This data release was created at the request of Mount Pleasant Waterworks to document the effects of a proposed well. This data release contains all of the model input and out files needed to run the model simulations described above. Data tables and figures of the model output are included in the ancillary directory. The data release also includes MODFLOW-2000 source code used to run the model simulations.