Dr. Langevin is an internationally recognized authority in the field of hydrologic modeling. He specializes in the development and application of advanced simulation software for complex groundwater resource evaluations and contaminant transport analyses. Prior to joining SSP&A, Dr. Langevin served as the lead developer and primary caretaker of the U.S. Geological Survey (USGS) MODFLOW program, the world’s most widely used groundwater simulator. In this pivotal role, he helped shape modern groundwater simulation tools. He has developed and codeveloped key hydrologic modeling software, including MODFLOW 6, MODFLOW-USG, MT3D-USGS, SEAWAT, and FloPy, and authored or coauthored numerous peer-reviewed publications and technical reports on hydrologic modeling.

His expertise in translating physical hydrologic systems into numerical representations comes from over two decades of practical application together with teaching and advising on the application of numerical models in diverse hydrologic settings. His specialized knowledge includes constant- and variable-density groundwater flow – emphasizing saltwater intrusion – solute and heat transport, efficient unstructured grid applications, and automated workflows for model construction, calibration, and predictive analysis. His project experience includes modeling integrated surface and groundwater systems, aquifer storage and recovery, deep-well injection, and coastal hydrology including seawater intrusion.

EDUCATION
  • PhD, Geology, University of South Florida, 1998
  • MS, Geology, University of South Florida, 1993
  • BS, Geology, University of Wisconsin-Madison, 1991
AREAS OF EXPERTISE
  • Quantitative Hydrogeology
  • Numerical Modeling of Groundwater Flow
  • Variable-Density Groundwater Flow
  • Solute Transport
  • Saltwater Intrusion
  • Development of Customized Hydrologic Modeling Software
  • Automated and Reproducible Modeling Workflows
AWARDS AND HONORS
  • Alumni Award, University of South Florida Geology Department: 2010
  • John Hem Award for Excellence in Science & Engineering, National Ground Water Association: 2008
ACADEMIC APPOINTMENTS
  • Courtesy faculty appointment, Florida International University, Department of Earth Sciences, Miami, FL: September 2007 – May 2010
  • Courtesy faculty appointment, University of Alabama, Graduate School, Tuscaloosa, AL: October 2004 – May 2010
  • Courtesy faculty appointment, University of Florida, Tropical Research and Education Center, Homestead, FL: August 2004 – 2010
  • Visiting Professor, University of Puerto Rico-Rio Piedras, Department of Environmental Studies: 2003 Summer Semester
  • Instructor, University of South Florida, Geology Department, Tampa, FL: 1994, 1995, 1996 Fall Semesters
COMMITTEES
  • 2024-Present: Steering Group Member, Groundwater Network of the Global Energy and Water Exchanges (GEWEX) Program
  • 2016: Team Leader and Lead Author, Office of Groundwater Technical Memorandum 2016.02— Policy for documenting, archiving, and public release of numerical groundwater flow and transport models
  • 2015: International Committee Participant, Danish International Network Programme
  • 2014: Team Member and Coauthor, Office of Groundwater Technical Memorandum 2015.02 – Policy and guidelines for archival of surface-water, groundwater, and water-quality model applications
  • 2006 – Present: Associate Editor, Groundwater Journal
  • 2000 – 2005: Technical Advisor, Aquifer Storage and Recovery Project Development Team of the Comprehensive Everglades Restoration Plan
  • 2002: Expert Consultant, Bureau of Indian Affairs for SEAWAT modeling study, Lummi Indian Reservation, Washington
  • 2002: International Expert Consultant, United Nations Food and Agricultural Organization, Rabat, Morocco
PROFESSIONAL SOCIETIES
  • National Ground Water Association (NGWA)
  • Geological Society of America (GSA)
  • American Geophysical Union (AGU)
SOFTWARE RELEASES
MODFLOW 6

MODFLOW 6 releases are listed below and also available on GitHub at: https://github.com/MODFLOW-ORG/modflow6/releases

  • Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J., Niswonger, R.G., Panday, Sorab, Merrick, Damian, Morway, E.D., Reno, M.J., Bonelli, W.P., Boyce, S.E., and Banta, E.R., 2025. MODFLOW 6 Modular Hydrologic Model version 6.6.1: U.S. Geological Survey Software Release, 10 February 2025. doi: 10.5066/P9FL1JCC

  • Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J., Niswonger, R.G., Panday, Sorab, Merrick, Damian, Morway, E.D., Reno, M.J., Bonelli, W.P., Boyce, S.E., and Banta, E.R., 2024. MODFLOW 6 Modular Hydrologic Model version 6.6.0: U.S. Geological Survey Software Release, 19 December. doi: 10.5066/P1DXFBUR

  • Langevin, C.D., Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J., Morway, E.D., Reno, M.J., Bonelli, W.P., Panday, Sorab, Merrick, Damian, Niswonger, R.G., Boyce, S.E., and Banta, E.R., 2024. MODFLOW 6 Modular Hydrologic Model version 6.5.0: U.S. Geological Survey Software Release, 23 May. doi: 10.5066/P13COJJM

  • Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J., Niswonger, R.G., Panday, Sorab, Merrick, Damian, Banta, E.R., Morway, E.D., Reno, M.J., and Bonelli, W.P., 2022. MODFLOW 6 Modular Hydrologic Model version 6.4.0: U.S. Geological Survey Software Release, 30 November. doi: 10.5066/P9FL1JCC

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2021. MODFLOW 6 Modular Hydrologic Model version 6.3.0 release candidate: U.S. Geological Survey Software Release, 4 March. doi: 10.5066/F76Q1VQV

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2021. MODFLOW 6 Modular Hydrologic Model version 6.2.2 release candidate: U.S. Geological Survey Software Release, 6 August. doi: 10.5066/F76Q1VQV

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2021. MODFLOW 6 Modular Hydrologic Model version 6.2.1: U.S. Geological Survey Software Release, 17 February. doi: 10.5066/F76Q1VQV

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2020. MODFLOW 6 Modular Hydrologic Model version 6.2.0: U.S. Geological Survey Software Release, 22 October. doi: 10.5066/F76Q1VQV

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2020. MODFLOW 6 Modular Hydrologic Model version 6.1.1: U.S. Geological Survey Software Release, 12 June. doi: 10.5066/F76Q1VQV

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Provost, A.M., Niswonger, R.G., and Panday, Sorab, 2018. MODFLOW 6 Modular Hydrologic Model version 6.1.0: U.S. Geological Survey Software Release. doi: 10.5066/F76Q1VQV

OTHER SOFTWARE

  • Mccreight, James L., Langevin, C.D., Hughes, J. D., Bonelli, W. P., 2024. pywatershed v2.0.0, U.S. Geological Survey Software Release. doi: 10.5066/P13EWPEV

  • Fienen M.N., Hughes, J.D., Langevin, C.D., Larsen, J.D., and Leaf, A.T. 2024. python-for-hydrology, U.S. Geological Survey software release. Reston, VA. doi: 10.5066/P1QTRYJY

  • Mccreight, James L., Langevin, C.D., Hughes, J. D., Bonelli, W. P., 2023. pywatershed v1.0.0, U.S. Geological Survey Software Release, 1 December. doi: 10.5066/P9AVWA7Z

  • Bedekar, Vivek, Morway, E.D., Langevin, C.D., and Tonkin, Matt, 2016. MT3D-USGS version 1: A U.S. Geological Survey release of MT3DMS updated with new and expanded transport capabilities for use with MODFLOW: U.S. Geological Survey Techniques and Methods 6-A53, 69 p. doi: 10.3133/tm6A53

  • Lien, Jyh-Ming, Liu, Guilin, and Langevin, C.D., 2015. GRIDGEN version 1.0—A computer program for generating unstructured finite-volume grids: U.S. Geological Survey Open-File Report 2014–1109, 26 p. doi: 10.3133/ofr20141109

  • Panday, Sorab, Langevin, C.D., Niswonger, R.G., Ibaraki, Motomu, and Hughes, J.D., 2013. MODFLOW-USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation: U.S. Geological Survey Techniques and Methods, book 6, chap. A45, 66 p. doi: 10.3133/tm6A45

  • Panday, Sorab, Langevin, C.D., Niswonger, R.G., Ibaraki, Motomu, and Hughes, J.D., 2013. MODFLOW-USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation: U.S. Geological Survey Techniques and Methods, book 6, chap. A45, 66 p. doi: 10.3133/tm6A45

PUBLICATIONS AND REPORTS
PEER-REVIEWED PUBLICATIONS

  • Morway, E.D., Provost, A.M., Langevin, C.D., Hughes, J.D., Russcher, M.J., Chen, C.Y., Lin, Y.F.F., 2025. A New Groundwater Energy Transport Model for the MODFLOW Hydrologic Simulator. Groundwater. doi: 10.1111/gwat.13470

  • Provost, A.M., Bardot, K., Langevin, C.D., McCallum, J.L., 2025. Accurate Simulation of Flow through Dipping Aquifers with MODFLOW 6 Using Enhanced Cell Connectivity. Groundwater. doi: 10.1111/gwat.13459

  • Langevin, C.D., Hughes, J.D., Provost, A.M., Russcher, M.J. and Panday, S. 2024. MODFLOW as a Configurable Multi- Model Hydrologic Simulator. Groundwater, 62: 111-123. doi: 10.1111/gwat.13351

  • Larsen, J.D., Langevin, C.D., Hughes, J.D. and Niswonger, R.G., 2024. An Agricultural Package for MODFLOW 6 Using the Application Programming Interface. Groundwater, 62: 157-166. doi: 10.1111/gwat.13367

  • Hughes, J.D., Langevin, C.D., Paulinski, S.R., Larsen, J.D. and Brakenhoff, D., 2024. FloPy Workflows for Creating Structured and Unstructured MODFLOW Models. Groundwater, 62: 124-139. doi: 10.1111/gwat.13327

  • Mancewicz, L.K., Mayer, A., Langevin, C.D., and Gulley, J., 2023. Improved Method for Simulating Groundwater Inundation Using the MODFLOW 6 Lake Transport Package. Groundwater, 61: 421-430. doi: 10.1111/gwat.13254

  • Herrera, P.A., Langevin, C.D. and Hammond, G., 2023. Estimation of the Water Table Position in Unconfined Aquifers with MODFLOW 6. Groundwater, 61: 648-662. doi: 10.1111/gwat.13270

  • Hughes, J.D., Russcher, M.J., Langevin, C.D., Morway, E.D., and McDonald, R.R., 2022. The MODFLOW Application Programming Interface for simulation control and software interoperability: Environmental Modelling & Software, v. 148, 105257. doi: 10.1016/j.envsoft.2021.105257

  • Morway, E.D., Langevin, C.D., and Hughes, J.D., 2021. Use of the MODFLOW 6 water mover package to represent natural and managed hydrologic connections: Groundwater, v. 59, no. 6, p. 913-924. doi: 10.1111/gwat.13117

  • Langevin, C.D., Panday, S. and Provost, A.M. 2020. Hydraulic-Head Formulation for Density-Dependent Flow and Transport. Groundwater, 58: 349-362. doi: 10.1111/gwat.12967

  • Provost, A.M., Werner, A.D., Post, V.E.A., Michael, H.A., and Langevin, C.D., 2018. Rebuttal to “The case of the Biscayne Bay and aquifer near Miami, Florida: density-driven flow of seawater or gravitationally driven discharge of deep saline groundwater?” by Weyer (Environ Earth Sci 2018, 77:1–16). Environ Earth Sci 77, 710. doi: 10.1007/s12665-018-7832-5

  • Panday, Sorab, Bedekar, Vivek, and Langevin, C.D., 2018. Impact of Local Groundwater Flow Model Errors on Transport and a Practical Solution for the Issue. Groundwater, 56: 667-672. doi: 10.1111/gwat.12627

  • Bakker, M., Post, V., Langevin, C. D., Hughes, J. D., White, J. T., Starn, J. J. and Fienen, M. N., 2016. Scripting MODFLOW model development using Python and FloPy. Groundwater 54 p. 733-739. doi: 10.1111/gwat.12413

  • Bakker, M., Post, V., Langevin, C. D., Hughes, J. D., White, J. T., Starn, J. J. and Fienen, M. N., 2016. Scripting MODFLOW model development using Python and FloPy. Groundwater 54 p. 733-739. doi: 10.1111/gwat.12413

  • Feinstein, D.T., Fienen, M.N., Reeves, H.W., and Langevin, C.D., 2016. A semi-structured MODFLOW-USG model to evaluate local water sources to wells for decision support. Groundwater 54 p. 532-544. doi: 10.1111/gwat.12389

  • Hughes, J.D., Langevin, C.D., and White, J.T., 2014. MODFLOW-based coupled surface water routing and groundwater-flow simulation. Groundwater 53 p. 452-463. doi: 10.1111/gwat.12216

  • Konikow, L.F., Akhavan, M., Langevin, C.D., Michael, H.A., and Sawyer, A.H., 2013. Seawater circulation in sediments driven by interactions between seabed topography and fluid density. Water Resources Research, Volume 49, Issue 3 p. 1386-1399. doi: 10.1002/wrcr.20121

  • Morway, E.D., Niswonger, R.G., Langevin, C.D., Bailey, R.T., and Healy, R.W., 2013. Modeling variably saturated subsurface solute transport with MODFLOW-UZF and MT3DMS. Ground Water 51 p. 237-251 doi: 10.1111/j.1745-6584.2012.00971.x

  • Langevin, C.D., and Zygnerski, M., 2013. Effect of sea- level rise on salt water intrusion near a coastal well field in southeastern Florida. Ground Water 51, p. 781-803. doi: 10.1111/j.17456584.2012.01008.x

  • La Licata, I., Langevin, C.D., Dausman, A.M., and Alberti, L., 2013. Effect of tidal fluctuations on transient dispersion of simulated contaminant concentrations in a coastal aquifer. Hydrogeology Journal, Vol. 18, no. 1: 25-38. doi: 10.1007/s10040-011-0763-9

  • Langevin, C.D., and Panday, S., 2012. Future of groundwater modeling. Ground Water 50 no. 3: 334-339. doi: 10.1111/j.1745-6584.2012.00937.x

  • Panday, S., and Langevin, C.D., 2012. Improving sub-grid scale accuracy of boundary features in regional finite-difference models. Advances in Water Resources 41: 65-75.

  • Hughes, J.D., Decker, J.D., and Langevin, C.D., 2011. Use of upscaled elevation and surface roughness data in two-dimensional surface water models. Advances in Water Resources, Vol. 34, no. 9: 1151-1164. doi: 10.1016/j.advwatres.2011.02.004

  • Herckenrath, D. Langevin, C.D., and Doherty, J., 2011. Predictive uncertainty analysis of a saltwater intrusion model using null-space Monte Carlo. Water Resources Research, Vol. 47, W05504. doi: 10.1029/2010WR009342

  • Mulligan, A.E., Langevin, C.D., and Post, V., 2011. Tidal boundary conditions in SEAWAT, Ground Water 49: 866-879. doi: 10.1111/j.1745-6584.2010.00788.x

  • Obeysekera, J., Kuebler, L., Ahmed, S., Chang, Miao-LI, Engel, V., Langevin, C., Swain, E., and Wan, Y., 2011. Use of Hydrologic and Hydrodynamic Modeling for Ecosystem Restoration. Critical Reviews in Environmental Science and Technology, 41: 6, 447-488.

  • Dausman, A. M., Doherty, J., Langevin, C. D. and Sukop, M. C., 2010. Quantifying data worth toward reducing predictive uncertainty. Ground Water, 48: 729–740. doi: 10.1111/j.1745-6584.2010.00679.x

  • Langevin, C. D., Dausman, A. M. and Sukop, M. C., 2010. Solute and heat transport model of the Henry and Hilleke laboratory experiment: Ground Water, 48: 757–770. doi: 10.1111/j.17456584.2009.00596.x

  • Dausman, A.M., Doherty, J., Langevin, C.D., and Dixon, J., 2010. Hypothesis testing of buoyant plume migration using a highly parameterized variable-density groundwater model at a site in Florida, USA. Hydrogeology Journal vol. 18, no. 1: 147-160. doi: 10.1007/s10040-009-0511-6

  • Hughes, J.D., Langevin, C.D., and Brakefield-Goswami, L., 2010. Effect of hypersaline cooling canals on aquifer salinization: Hydrogeology Journal vol. 18, no. 1: 25-38. doi: 10.1007/s10040009-0502-7

  • Langevin, C.D., 2008. Modeling axisymmetric flow and transport: Ground Water vol. 46, no. 4:579-590.

  • Swain, E.D., Langevin, C.D., and Wang, J.D., 2008. Utilizing spectral analysis of coastal discharge computed by a numerical model to determine boundary influence. Journal of Coastal Research, vol. 24, no. 6: 1418-1429.

  • Thorne, D., Langevin, C.D., and Sukop, M.C., 2006. Addition of simultaneous heat and solute transport and variable fluid viscosity to SEAWAT: Computer and Geosciences vol. 32, 1758-1768.

  • Langevin, C.D. and Guo, W., 2006. MODFLOW/MT3DMS- based simulation of variable density ground water flow and transport: Ground Water vol. 44, no. 3:339-351.

  • Mao, X., Prommer, H., Barry, D.A., Langevin, C.D., Panteleit, B., and Li, L., 2006. Three-dimensional model for multi- component reactive transport with variable density groundwater flow: Environmental Modelling & Software vol. 21, no. 5:615-628.

  • Langevin, C.D., Swain, E.D., and Wolfert, M.A. 2005. Simulation of integrated surface-water/groundwater flow and salinity for a coastal wetland and adjacent estuary: Journal of Hydrology 314, 212234.

  • Bakker, M., Oude Essink, G.H.P., and Langevin, C.D. 2004. The rotating movement of three immiscible fluids a benchmark problem. Journal of Hydrology 287, 270-278.

  • Langevin, C.D. 2003b. Simulation of submarine ground water discharge to a marine estuary: Biscayne Bay, Florida. Ground Water 41, no. 6: 758-771.

  • Langevin, C.D. 2003a. Stochastic ground water flow simulation with a fracture zone continuum model. Ground Water 41, no. 5: 587-601.

  • Stewart, M.T., and Langevin, C.D. 1999. Post Audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system. Ground Water 37, no. 2:245-252.

  • Langevin, C.D., Stewart, M.T., and Beaudoin, C.M. 1998. Effects of dredge and fill canals on freshwater resources of small oceanic islands. An example from Big Pine Key, Florida. Ground Water 36, no. 3: 503-513.

PUBLISHED REPORTS, CONFERENCE PAPERS, AND DATA RELEASES

  • Morway, E., Provost, A., and Langevin, C.D., 2025. Two 2-Dimensional models patterned after the Barends analytical solution for verifying the accuracy of the new Groundwater Energy (GWE) Transport model built for the MODFLOW 6 hydrologic simulator: U.S. Geological Survey data release. doi: 10.5066/P13KJF3C

  • Provost, A.M., Bardot, K., Langevin, C.D., and McCallum, J.L., 2025. MODFLOW 6 models used to evaluate the accuracy of enhanced cell connectivity for simulation of flow through dipping aquifers: U.S. Geological Survey data release. doi: 10.5066/P13BNARA

  • Langevin, C.D., Provost, A.M., Panday, Sorab, and Hughes, J.D., 2022. Documentation for the MODFLOW 6 Groundwater Transport (GWT) Model: U.S. Geological Survey Techniques and Methods, book 6, chap. A61, 56 p. doi: 10.3133/tm6A61

  • Morway, E.D., Langevin, C.D., Hughes, J.D., 2021. MODFLOW 6 model of two hypothetical stream- aquifer systems to demonstrate the utility of the new Water Mover Package (MVR) available only with MODFLOW 6: U.S. Geological Survey data release. doi: 10.5066/P9GQETP9

  • Provost, A.M., Langevin, C.D., and Hughes, J.D., 2017. Documentation for the “XT3D” option in the Node Property Flow (NPF) Package of MODFLOW 6: U.S. Geological Survey Techniques and Methods 6–A56, 40 p. doi: 10.3133/tm6A56

  • Langevin, C.D., Hughes, J.D., Banta, E.R., Niswonger, R.G., Panday, Sorab, and Provost, A.M., 2017. Documentation for the MODFLOW 6 Groundwater Flow Model: U.S. Geological Survey Techniques and Methods 6–A55, 197 p. doi: 10.3133/tm6A55

  • Hughes, J.D., Langevin, C.D., and Banta, E.R., 2017. Documentation for the MODFLOW 6 framework: U.S. Geological Survey Techniques and Methods 6–A57, 42 p. doi: 10.3133/tm6A57

  • Bakker, M., Schaars, F., Hughes, J.D., and Langevin, C.D., 2013. The sea water intrusion (SWI2) Package for modeling vertically-integrated variable density groundwater flow in regional aquifers with the U.S. Geological Survey Modular Groundwater Model (MODFLOW-2005). U.S. Geological Survey Techniques and Methods, 6-A46, 47 p.

  • Ibaraki, M., Panday, S., Niswonger, R.G., Langevin, C.D., 2013. Improvement of performance of MODFLOW xMD matrix solver package for heterogeneous computing environments. MODFLOW and More 2013: Translating Science Into Practice, Golden, Colorado, June 2-5.

  • Bakker, M., Post, V., Hughes, J., Langevin, C., Frances, A., White, J., 2013. Enhanced FloPy scripts for constructing and running MODFLOW-based models. MODFLOW and More 2013: Translating Science Into Practice, Golden, Colorado, June 2-5.

  • Feinstein, D.T., M.N. Fienen, H.W. Reeves, and Langevin, C.D., 2013. Application of a “semistructured” approach with MODFLOW-USG to simulate local groundwater/ surface-water interactions at the regional scale as basis for a decision-support tool. MODFLOW and More 2013: Translating Science Into Practice, Golden, Colorado, June 2-5.

  • Brakefield, L., Hughes, J.D., Langevin, C.D., and Chartier, K., 2013. Estimation of capture zones and drawdown at the Northwest and West Well Fields, Miami-Dade County, Florida, using an unconstrained Monte Carlo analysis: recent (2004) and proposed conditions: U.S. Geological Survey Open-File Report 2013–1086, 124 p. http://pubs.usgs.gov/of/2013/1086

  • Hughes, J.D., Langevin, C.D., Chartier, K.L., and White, J.T., 2012. Documentation of the Surface Water Routing (SWR1) Process for modeling surface-water flow with the U.S. Geological Survey Modular Groundwater Model (MODFLOW-2005), U.S. Geological Survey Techniques and Methods 6-A40.

  • Ibaraki, M., Panday, S., Niswonger, R.G., and Langevin, C.D., 2011. Improvement of performance of MODFLOW: XMD matrix solver package. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Provost, A.M. and Langevin, C.D., 2011. Effect of the difference between water-table elevation and hydraulic head on simulation of unconfined aquifers using MODFLOW. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Brakefield, L.K., Langevin, C.D., and Hughes, J.D., 2011. Estimating well-field contributing areas in the presence of lakes using an unconstrained Monte-Carlo analysis. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Hughes, J.D., White, J.T., Brakefield, L.K., Walsh, V.M., Langevin, C.D., 2011. Simulating surface-water control structures and surface-water/groundwater interactions in Miami-Dade County, Florida, using the Surface-Water Routing Process for MODFLOW-2005. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Schaars, F.W., Bakker, M., Hughes, J.D., Dausman, A.M., Langevin, C.D., 2011. Modeling regional seawater intrusion with MODFLOW2005 and the SWI Package. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Langevin, C.D., Panday, S., Niswonger, R.G., Hughes, J.D., Ibaraki, M., 2011. Local grid refinement with an unstructured grid version of MODFLOW. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • Panday, S., Niswonger, R.G., Langevin, C.D., Ibaraki, M., 2011. An un-structured grid version of MODFLOW. In MODFLOW and More 2011: Integrated Hydrologic Modeling – Conference Proceedings, June 5 – 8, 2011, International Groundwater Modeling Center, Colorado School of Mines.

  • White, J.T., Langevin, C.D., and Hughes, J.D. 2010. Evaluating the effect of Tikhonov regularization schemes on predictions in a variable-density groundwater model. SWIM21 – 21st Salt Water Intrusion Meeting Proceedings Book, Ponta Delgada, Azores, Portugal, June 21-26.

  • Hughes, J.D., White, J.T., and Langevin, C.D. 2010. Use of time series and harmonic constituents of tidal propagation to enhance estimation of coastal aquifer heterogeneity. SWIM21 – 21st Salt Water Intrusion Meeting Proceedings Book, Ponta Delgada, Azores, Portugal, June 21-26, 2010.

  • Dausman, A.M., Langevin, C.D., Bakker, M., and Schaars, 2010. A comparison between SWI and SEAWAT – the importance of dispersion, inversion, and vertical anisotropy. SWIM21 – 21st Salt Water Intrusion Meeting Proceedings Book, Ponta Delgada, Azores, Portugal, June 21-26.

  • Langevin, C.D., Zygnerski, M.R., White, J.T., and Hughes, J.D. 2010. Effect of sea-level rise on future coastal groundwater resources in southern Florida, USA. SWIM21 – 21st Salt Water Intrusion Meeting Proceedings Book, Ponta Delgada, Azores, Portugal, June 21-26.

  • Condesso de Melo, M.T., Lebbe, L., Cruz, J.V., Coutinho, R., Langevin, C.D., and Buxo, A., eds. 2010. SWIM21 – 21st Salt Water Intrusion Meeting Proceedings Book, Ponta Delgada, Azores, Portugal, June 21-26, 2010. 373 p.

  • Dausman, A., Langevin, C.D., Thorne, D., Sukop, M.C., 2009. Six benchmark problems for testing heat and solute transport with variable viscosity using SEAWAT Version 4: U.S. Geological Survey Scientific Investigations Report 2009-5028, 72 p.

  • Dausman, A.M., Doherty, J., and Langevin, C.D., 2009. Creative use of pilot points to address site and regional scale heterogeneity in a variable-density model. The PEST conference 2009, November 2-4, Potomac, Maryland.

  • Herckenrath, D. Langevin, C.D., and Doherty, J., 2009. Application of a null space Monte Carlo method to a salt water intrusion model. The PEST conference 2009, November 2-4, Potomac, Maryland.

  • Brakefield, L., Langevin, C.D., Use of unconstrained Monte Carlo methods to determine effects of uncertainty in hydraulic conductivity and effective porosity on well-field contributing areas. The PEST conference 2009, November 2-4, Potomac, Maryland.

  • Langevin, C.D., and Hughes, J.D., 2009. Effect of numerical dispersion as a source of structural noise in the calibration of a highly parameterized saltwater intrusion model. The PEST conference 2009, November 2-4, Potomac, Maryland.

  • Yager, R.M., Misut, P.E., Langevin, C.D., and Parkhurst, D.L., 2009. Brine migration from a flooded salt mine in the Genesee Valley, Livingston County, New York: Geochemical modeling and simulation of variable-density flow: U.S. Geological Survey Professional Paper 1767, 59 p., also available online at http://pubs.usgs.gov/pp/pp1767/

  • Langevin, C.D., Lebbe, L., Bakker, M., and Voss, C., eds., 2008. 20th Salt Water Intrusion Meeting, Program and Proceedings, June 23-27, Naples, Florida, U.S.A., 340 p.

  • Brakefield, L.K., Abarca, E., Langevin, C.D., and Clement, T.P., 2008. Physical and numerical modeling of buoyant groundwater plumes: In Proceedings of the 20th Salt Water Intrusion Meeting, June 23-27, Naples, Florida, U.S.A.

  • La Licata, I., Langevin, C.D., Dausman, A.M., and Alberti, L., 2008. Tidal effects on transient dispersion of simulated contaminant concentrations in coastal aquifers: In Proceedings of the 20th Salt Water Intrusion Meeting, June 23-27, Naples, Florida, U.S.A.

  • Zygnerski, M.R., and Langevin, C.D., 2008. Quantifying effects of natural and anthropogenic stresses on long-term saltwater intrusion in a coastal aquifer: In Proceedings of the 20th Salt Water Intrusion Meeting, June 23-27, Naples, Florida, U.S.A.

  • Dausman, A.M., Langevin, C.D., Sukop, M.C., and Walsh, V., 2008b. Saltwater/freshwater interface movement in response to deep-well injection in a coastal aquifer: In Proceedings of the 20th Salt Water Intrusion Meeting, June 23-27, Naples, Florida, U.S.A.

  • Bittner, L.D., Richardson, E., Langevin, C.D., England, S.M., and Stevens, G.T., 2008. Using density-dependent numerical models to evaluate regional groundwater flow patterns in South Florida: In Proceedings of The World Environmental & Water Resources Congress, May 12-16, Honolulu, Hawaii.

  • Sukop, M.C., S. Anwar, J.S. Lee, K.J. Cunningham, and C.D. Langevin, 2008. Modeling groundwater flow and solute transport in karst with Lattice Boltzmann Methods: Proceedings of the U.S. Geological Survey Karst Interest Group Workshop, May 27-29, Bowling Green, Kentucky, Western Kentucky University Campus. http://pubs.usgs.gov/sir/2008/5023/32sukop.htm

  • Dausman, A., Doherty, J., Langevin, C.D., and Sukop, M.C., 2008. Quantifying data contributions toward reducing predictive uncertainty in a variable-density flow and solute/ heat transport model: In MODFLOW and More 2008: Ground Water and Public Policy Conference Proceedings, Golden, Colorado, May 19-21.

  • Langevin, C.D., Dausman, A.M., Thorne, D., and Sukop, M.C., 2008. Modeling solute and heat transport with SEAWAT: In MODFLOW and More 2008: Ground Water and Public Policy Conference Proceedings, Golden, Colorado, May 19-21.

  • Wolfert-Lohmann, M.A., Langevin, C.D., Jones, S.A., Reich, C.D., Wingard, G.L., Kuffner, I.B., and Cunningham, K.J., 2008. U.S. Geological Survey science support strategy for Biscayne National Park and surrounding areas in Southern Florida: U.S. Geological Survey Open-File Report 2007-1288, 47 p.

  • Zygnerski, M.R., and Langevin, C.D., 2007. Long-term saltwater intrusion in a coastal limestone aquifer: quantifying effects of natural and anthropogenic stress: In Proceedings of the 3rd International Symposium on Technology of Seawater Intrusion into Coastal Aquifers, Almeria, Spain, October 16-19.

  • Langevin, C.D., Lebbe, L., Bakker, M., and Voss, C.I., 2007, Ground Water Readers’ Forum: Twentieth salt water intrusion meeting planned for June 23 to 27, 2008, in Naples, Florida. Ground Water 46, no. 6: 657-658.

  • La Licata, I., Langevin, C.D., Dausman, A.M., 2007. Effect of tidal fluctuations on contaminant transfer to the ocean, in Sanford, W., Langevin, C.D., Polemio, M., and Povinec. P., eds., 2007, A new focus on groundwater-seawater interactions: IAHS Publication 312, Oxfordshire, United Kingdom, p. 334-341.

  • Dausman, A.M., Langevin, C.D., Sukop, M.C., 2007. Simulation of submarine groundwater discharge salinity and temperature variations: implications for remote detection, in Sanford, W., Langevin, C.D., Polemio, M., and Povinec. P., eds., 2007, A new focus on groundwater-seawater interactions: IAHS Publication 312, Oxfordshire, United Kingdom, p. 272-280.

  • Langevin, C.D., Sanford, W., Polemio, M., and Povinec, P., 2007. Background and summary, in Sanford, W., Langevin, C.D., Polemio, M., and Povinec. P., eds., 2007, A new focus on groundwater-seawater interactions: IAHS Publication 312, Oxfordshire, United Kingdom, p. 3-10.

  • Sanford, W., Langevin, C.D., Polemio, M., and Povinec. P., eds., 2007. A new focus on groundwater-seawater interactions: IAHS Publication 312, Oxfordshire, United Kingdom, 344 p.

  • Wang, J.D., Swain, E.D., Wolfert, M.A., Langevin, C.D., James, D.E., and Telis, P.A., 2007. Application of FTLOADDS to Simulate Flow, Salinity, and Surface-Water Stage in the Southern Everglades, Florida: U.S. Geological Survey Scientific Investigations Report 2007–5010, 112 p.

  • Langevin, C.D., 2007b. Section 4.6. Groundwater discharge to Biscayne Bay, Florida: In Submarine Groundwater, (eds.) I. Zektser and R. Dzhamalov, CRC Press.

  • Langevin, C.D., 2007a. Section 2.1.2. Numerical simulation of submarine groundwater discharge: In Submarine Groundwater, Zektser, I.S., and Dzhamalov, R.G. (eds.), CRC Press.

  • Langevin, C.D., and Zygnerski, M., 2006. Axisymmetric simulation of aquifer storage and recovery with SEAWAT and the Sea Water Intrusion (SWI) Package for MODFLOW: In Proceedings of MODFLOW and More 2006, Managing Ground-Water Systems, Golden, Colorado, May 22-24.

  • Thorne, D., Langevin, C.D., and Sukop, M.C., 2006. MODFLOW/MT3DMS-based simulation of variable- density groundwater flow with simultaneous heat and solute transport: In Proceedings of the 2006 Conference on Computational Methods in Water Resources XVI, Copenhagen, Denmark, June 19-22, 2006.

  • Langevin, C.D. and Dausman, A.M. 2005. Numerical simulation of saltwater intrusion in response to sea-level rise: In Proceedings of the World Water & Environmental Resources Congress, Impacts of Global Climate Change, American Society of Civil Engineers, Anchorage, Alaska, May 15-19, 2005.

  • Dausman, A.M. and Langevin, C.D. 2005. Movement of the saltwater interface in the Surficial Aquifer System in response to hydrologic stresses and water-management practices, Broward County, Florida: U.S. Geological Survey Scientific Investigations Report 2004-5256

  • Wolfert, M.A., Dausman, A., Langevin, C.D., Swain, E.D., and Wang, J.D., 2005. Using numerical models to simulate surface-water and ground-water movement in South Florida: USGS Science in Florida, Proceedings of Florida Integrated Science Center Meeting, Orlando, Florida, May 3-5. U.S. Geological Survey Open-File Report 2005-1213

  • Langevin, C.D., and Bean, D.M. 2005. Software Spotlight/ Ground Water Vistas: A graphical user interface for the MODFLOW family of ground water flow and transport models. Ground Water 43, no. 2:1-4.

  • Swarzenski, P.W., Charette, M., and Langevin, C.D. 2004. An autonomous, electromagnetic seepage meter to study coastal groundwater/surface water exchange: U.S. Geological Survey Open-File Report 2004-1369. doi: 10.3133/ofr20041369

  • Wolfert, M.A., Langevin, C.D., and Swain, E.D. 2004. Assigning boundary conditions to the Southern Inland and Coastal Systems (SICS) model using results from the South Florida Water Management Model (SFWMM): U.S. Geological Survey Open-File Report 2004-1195, 30 p. doi: 10.3133/ofr20041195

  • Langevin, C.D., Swain, E.D., Wang, J.D., Wolfert, M.A., Schaffranek, R.W., and Riscassi, A.L. 2004c. Development of coastal flow and transport models in support of Everglades restoration: U.S. Geological Survey Fact Sheet 2004-3130

  • Langevin, C.D., Swain, E.D., and Wolfert, M.A. 2004b. Simulation of integrated surface-water/groundwater flow and salinity for a coastal wetland and adjacent estuary, U.S. Geological Survey Open-File Report 2004-1097

  • Langevin, C.D., Oude Essink, G.H.P., Panday, S., Bakker, M., Prommer, H., Swain, E.D., Jones, W., Beach, M., and Barcelo, M. 2004a. Chapter 3, MODFLOW-based tools for simulation of variable-density groundwater flow: In Coastal Aquifer Management: Monitoring, Modeling, and Case Studies, (eds.) A. Cheng and D. Ouazar, Lewis Publishers, 49-76.

  • Langevin, C.D., Shoemaker, W.B., and Guo, W. 2003. MODFLOW-2000, the U.S. Geological Survey modular ground-water model—Documentation of the SEAWAT-2000 version with the variabledensity flow process (VDF) and the integrated MT3DMS Transport Process (IMT): U.S. Geological Survey Open-File Report 03-426, 43 p. doi: 10.3133/ofr03426

  • Langevin, C.D., Swain, E.D., and Wolfert, M.A. 2002. Numerical simulation of integrated surfacewater/ground- water flow and solute transport in the southern Everglades in Florida. Second Federal Interagency Hydrologic Modeling Conference, Las Vegas, Nevada, July 28- August 1.

  • Dausman, A., and Langevin, C.D. 2002. Representing hydrodynamic dispersion in saltwater intrusion models of different temporal scales. American Water Resources Association’s Spring Specialty Conference on ”Coastal Water Resources”, May 13-15, New Orleans, Louisiana.

  • Swain, E.D., Langevin, C.D., and Wolfert, M.A. 2002. Cooperative linking of numerical models for coastal wetland planning. American Water Resources Association’s Spring Specialty Conference on ”Coastal Water Resources,” May 13-15, New Orleans, Louisiana.

  • Guo, Weixing, and Langevin, C.D. 2002b. User’s guide to SEAWAT: A computer program for simulation of three-dimensional variable-density ground-water flow: U.S. Geological Survey Techniques of Water Resources Investigations Book 6, Chapter A7, 79 p.

  • Guo, Weixing, and Langevin, C.D. 2002a. User’s guide to SEAWAT: A computer program for simulation of three-dimensional variable-density ground-water flow: U.S. Geological Survey OpenFile Report 01-434, 79 p. doi: 10.3133/twri06A7

  • Langevin, C.D. 2001. Simulation of ground-water discharge to Biscayne Bay, Southeastern Florida: U.S. Geological Survey Water-Resources Investigations Report 00-4251, 127 p. doi: 10.3133/wri004251

  • Guo, Weixing, Langevin, C.D., and Bennett, G.D. 2001. Improvements to SEAWAT and application of the variable- density modeling program in southern Florida, in Poeter, E., and others, MODFLOW 2001 and Other Modeling Odysseys Conference, Colorado School of Mines, Golden, Colorado, 2, p. 621-627.

  • Stewart, M.T., and Langevin, C.D. 2000. AUTHOR’S REPLY. Ground Water 38, no. 1: 6-6.

  • Langevin, C.D. 1998. Stochastic methods for evaluating the potential for wetland rehydration in covered-karst terranes. Ph.D. Dissertation, University of South Florida.

  • Langevin, C.D. 1994. Numerical model of porewater fluxes in a hypothetical Florida Bay mud island. Master’s Thesis, University of South Florida.