MODFLOW-2005 and MODPATH6 models used to simulate groundwater flow and transport and base-flow age in two tributaries to the Upper Chester River, Maryland

Wesley O. Zell Ward E. Sanford 2018 MODFLOW-2005 and MODPATH6 models used to simulate groundwater flow and transport and base-flow age in two tributaries to the Upper Chester River, Maryland Version 1.0 groundwater model Reston, VA, USA U.S. Geological Survey https://doi.org/10.5066/F7SN087R Wesley O. Zell Teresa B. Culver Ward E. Sanford 2018 Prediction uncertainty and data worth assessment for groundwater transport times in an agricultural catchment. Journal article Journal of Hydrology Volumne 561, June 2018, p. 1019-1036 Amsterdam, Netherlands Elsevier https://doi.org/10.1016/j.jhydrol.2018.02.006 A steady state three-dimensional groundwater flow (MODFLOW-2005) and advective transport (MODPATH6) model was developed to examine subsurface travel times to wells and receiving streams in two subcatchments contributing to the Upper Chester River, Maryland. The model was calibrated to conditions from 1990 to 2005, the period for which groundwater levels, stream discharge measurements, and atmospheric tracer measurements were jointly available. Six calibrated model scenarios were generated and paired with First Order Second Moment (FOSM) linear uncertainty analysis tools to evaluate (i) the uncertainty of base-flow age estimates as well as (ii) the worth of future data collection. The development of the model input and output files included in this data release are documented in the Journal of Hydrology article (https://doi.org/10.1016/j.jhydrol.2018.02.006). This groundwater model was created to simulate subsurface travel times from recharge locations to discharge in two Maryland streams - Morgan Creek and Chesterville Branch - and to evaluate the worth of collecting additional head or atmospheric tracer data for purposes of reducing the uncertainty of estimated base-flow ages in those streams. The development of the model input and output files included in this data release are documented in the Journal of Hydrology article (https://doi.org/10.1016/j.jhydrol.2018.02.006). Support is provided for correcting errors in the data release and clarification of the modeling conducted by the U.S. Geological Survey. Users are encouraged to review the model documentation report (https://doi.org/10.1016/j.jhydrol.2018.02.006) to understand the purpose, construction, and limitations of this model. The models, along with pre- and post-processing tools, will run successfully only if the original directory structure is correctly restored. The model archive is broken into several pieces to reduce the likelihood of download timeouts. Instructions for reconstructing the original directory structure and running the models included in this data release and described in the model documentation report can be found in the readme.txt ASCII file which can be downloaded as part of this data release. 19900101 20051103 2018 Complete not planned -76.01677 -75.89283 39.33294 39.25341 USGS Thesaurus usgsgroundwatermodel MODFLOW2005 Groundwater InlandWaters Groundwater Model Transport Model MODPATH6 ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Metadata Identifier USGS:acd82fec-a6b3-4917-b5e5-c8bc2cb28514 Geographic Information Names System Maryland Aquia aquifer Chester River Kent County None. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from this data release. none Wesley O. Zell U.S. Geological Survey mailing and physical

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Reston VA 20192 USA 703-648-5835 wzell@usgs.gov https://water.usgs.gov/GIS/browse/zell2018_upperchesterthumbnail.jpg Image of the model domain and active area of the model. jpg U.S. Geological Survey National Research Program The model was calibrated to conditions from 1990 to 2005, the period for which groundwater levels, stream discharge measurements, and atmospheric tracer measurements were jointly available. The calibration process was constrained by water-level data from 69 groundwater monitoring wells with 10 or more measurements, annually-averaged discharge in Morgan Creek and Chesterville Branch, and atmospheric tracer concentrations (SF6, CFC11, CFC12, CFC113, and 3H) at 31 wells. No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record and the associated model documentation report (https://doi.org/10.1016/j.jhydrol.2018.02.006) for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted The process used to develop, calibrate, and apply the model is fully described in the model documentation report (https://doi.org/10.1016/j.jhydrol.2018.02.006). 2018 raster pixel Transverse Mercator 0.9996 -75.0 0.0 500000.0 0.0 row and column 75.0 75.0 meters North American Vertical Datum of 1983 1.0 meters Attribute values zell2018_upperchester.shp ESRI Polygon shapefile U.S. Geological Survey Area Text string indicating that the polygon area is active or inactive in the model. https://doi.org/10.1016/j.jhydrol.2018.02.006 usgsgroundwatermodel Delineation of active and inactive areas in the model. https://doi.org/10.1016/j.jhydrol.2018.02.006 Zell, W.O., and Sanford, W.E., 2018, MODFLOW-2005 and MODPATH6 models used to simulate groundwater flow and transport and base-flow age in two tributaries to the Upper Chester River, Maryland: U.S. Geological Survey data release https://doi.org/10.5066/F7SN087R U.S. Geological Survey Michael Ierardi IT Specialist mailing and physical

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Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov Although the data have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, the data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from authorized or unauthorized use. Although the data, software, and related material have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. readme.txt 1.0 ASCII text file This ASCII text file describes the model data release. This file also includes descriptions of the model input and output files and instructions on how to run the models contained in this data release. 0.020189 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/readme.txt modelgeoref.txt 1.0 ASCII text file This ASCII text file defines the four corners of the model domain in decimal degrees. 0.000730 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/modelgeoref.txt ancillary.zip 1.0 ZIP This ZIP file contains ancillary data including additional scenario output such as PEST results, python scripts for post-processing model input and output along as well as data that was used to construct the model framework and observation data sets used in calibration. 1032.195008 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/ancillary.zip bin.zip 1.0 ZIP file ZIP file containing the 64-bit executable used to run all simulations documented in the report. 13.388888 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/bin.zip georef.zip 1.0 ZIP file ZIP file containing a shapefile which defines the extent of the model domain and active portions of the model. 0.008769 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/georef.zip model.zip 1.0 ZIP file This ZIP file contains the input files for all simulations documented in the report. 27.144576 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/model.zip output.zip 1.0 ZIP file This ZIP file contains the output files for all simulations documented in the report. 157.249844 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/output.zip source.zip 1.0 ZIP file ZIP file containing Source files for code versions used to run model simulations included in the data release. 5.190185 https://water.usgs.gov/GIS/dsdl/gwmodels/zell2018_upperchester/source.zip None 20201117 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998