Christian Langevin
Biography
Dr. Christian Langevin is a research hydrologist with the U.S. Geological Survey Earth Systems Modeling Branch. He presently sits in the Mounds View Office in Minnesota, which is part of the Upper Midwest Water Science Center. Dr. Langevin is the primary USGS contact for the MODFLOW program, which is used worldwide to simulate groundwater flow. His present research focuses on development and support of the MODFLOW 6 program and other related programs, such as FloPy, SEAWAT, MT3D-USGS, MODFLOW-USG, and MODFLOW-2005. Dr. Langevin began his career with the USGS in 1998 after completing his M.S. and Ph.D. at the University of South Florida in Tampa and his B.S. at the University of Wisconsin at Madison.
Science and Products
MODFLOW and Related Programs
MODFLOW is the USGS's modular hydrologic model. MODFLOW is considered an international standard for simulating and predicting groundwater conditions and groundwater/surface-water interactions. MODFLOW 6 is presently the core MODFLOW version distributed by the USGS. The previous core version, MODFLOW-2005, is actively maintained and supported as well.
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)
A recent paper by Weyer (Environ Earth Sci 2018, 77:1–16) challenges the widely accepted interpretation of groundwater heads and salinities in the coastal Biscayne aquifer near Miami, Florida, USA. Weyer (2018) suggests that the body of saltwater that underlies fresh groundwater just inland of the coast is not a recirculating wedge of seawater,...
Provost, Alden M.; Werner, Adrian D.; Post, Vincent E. A.; Michael, Holly A.; Langevin, Christian D.
Documentation for the MODFLOW 6 Groundwater Flow Model
This report documents the Groundwater Flow (GWF) Model for a new version of MODFLOW called MODFLOW 6. The GWF Model for MODFLOW 6 is based on a generalized control-volume finite-difference approach in which a cell can be hydraulically connected to any number of surrounding cells. Users can define the model grid using one of three discretization...
Langevin, Christian D.; Hughes, Joseph D.; Banta, Edward R.; Niswonger, Richard G.; Panday, Sorab; Provost, Alden M.
Documentation for the MODFLOW 6 framework
MODFLOW is a popular open-source groundwater flow model distributed by the U.S. Geological Survey. Growing interest in surface and groundwater interactions, local refinement with nested and unstructured grids, karst groundwater flow, solute transport, and saltwater intrusion, has led to the development of numerous MODFLOW versions. Often times,...
Hughes, Joseph D.; Langevin, Christian D.; Banta, Edward R.
Documentation for the “XT3D” option in the Node Property Flow (NPF) Package of MODFLOW 6
This report describes the “XT3D” option in the Node Property Flow (NPF) Package of MODFLOW 6. The XT3D option extends the capabilities of MODFLOW by enabling simulation of fully three-dimensional anisotropy on regular or irregular grids in a way that properly takes into account the full, three-dimensional conductivity tensor. It can also improve...
Provost, Alden M.; Langevin, Christian D.; Hughes, Joseph D.
MT3D-USGS version 1: A U.S. Geological Survey release of MT3DMS updated with new and expanded transport capabilities for use with MODFLOW
MT3D-USGS, a U.S. Geological Survey updated release of the groundwater solute transport code MT3DMS, includes new transport modeling capabilities to accommodate flow terms calculated by MODFLOW packages that were previously unsupported by MT3DMS and to provide greater flexibility in the simulation of solute transport and reactive solute transport...
Bedekar, Vivek; Morway, Eric D.; Langevin, Christian D.; Tonkin, Matthew J. Scripting MODFLOW model development using Python and FloPy
Graphical user interfaces (GUIs) are commonly used to construct and postprocess numerical groundwater flow and transport models. Scripting model development with the programming language Python is presented here as an alternative approach. One advantage of Python is that there are many packages available to facilitate the model development process...
Bakker, Mark; Post, Vincent E. A.; Langevin, Christian D.; Hughes, Joseph D.; White, Jeremy T.; Starn, Jeffrey; Fienen, Michael N. A semi-structured MODFLOW-USG model to evaluate local water sources to wells for decision support
In order to better represent the configuration of the stream network and simulate local groundwater-surface water interactions, a version of MODFLOW with refined spacing in the topmost layer was applied to a Lake Michigan Basin (LMB) regional groundwater-flow model developed by the U.S. Geological. Regional MODFLOW models commonly use coarse grids...
Feinstein, Daniel T.; Fienen, Michael N.; Reeves, Howard W.; Langevin, Christian D.
GRIDGEN Version 1.0: a computer program for generating unstructured finite-volume grids
GRIDGEN is a computer program for creating layered quadtree grids for use with numerical models, such as the MODFLOW–USG program for simulation of groundwater flow. The program begins by reading a three-dimensional base grid, which can have variable row and column widths and spatially variable cell top and bottom elevations. From this base...
Lien, Jyh-Ming; Liu, Gaisheng; Langevin, Christian D. MODFLOW-based coupled surface water routing and groundwater-flow simulation
In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a...
Hughes, Joseph D.; Langevin, Christian D.; White, Jeremy T. Effect of tidal fluctuations on transient dispersion of simulated contaminant concentrations in coastal aquifers
Variable-density groundwater models require extensive computational resources, particularly for simulations representing short-term hydrologic variability such as tidal fluctuations. Saltwater-intrusion models usually neglect tidal fluctuations and this may introduce errors in simulated concentrations. The effects of tides on simulated...
La Licata, Ivana; Langevin, Christian D.; Dausman, Alyssa M.; Alberti, Luca Effects of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida
A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt...
Langevin, Christian D.; Zygnerski, Michael
Documentation of the seawater intrusion (SWI2) package for MODFLOW
The SWI2 Package is the latest release of the Seawater Intrusion (SWI) Package for MODFLOW. The SWI2 Package allows three-dimensional vertically integrated variable-density groundwater flow and seawater intrusion in coastal multiaquifer systems to be simulated using MODFLOW-2005. Vertically integrated variable-density groundwater flow is based on...
Bakker, Mark; Schaars, Frans; Hughes, Joseph D.; Langevin, Christian D.; Dausman, Alyssa M.
FloPy: Python Package for Creating, Running, and Post-Processing MODFLOW-Based Models
FloPy is a Python package for creating, running, and post-processing MODFLOW-based models.
MODFLOW 6: USGS Modular Hydrologic Model
MODFLOW is a popular open-source groundwater flow model distributed by the U.S. Geological Survey.
MODFLOW-2005: USGS Three-Dimensional Finite-Difference Ground-Water Model
MODFLOW 6 is presently the core MODFLOW version distributed by the USGS, but MODFLOW-2005 (the previous core version) is still actively maintained and supported. MODFLOW-2005 simulates steady and nonsteady flow in an irregularly shaped flow system in which aquifer layers can be confined,...
MODFLOW-USG: An Unstructured Grid Version of MODFLOW for Simulating Groundwater Flow and Tightly Coupled Processes Using a Control Volume Finite-Difference Formulation
MODFLOW-USG is an unstructured grid version of MODFLOW for simulating groundwater flow and tightly-coupled processes using a control volume finite-difference formulation.
GRIDGEN: A Program for Generating Unstructured Finite-Volume Grids
GRIDGEN is a program for generating layered quadtree grids for MODFLOW-USG.
SEAWAT: A Computer Program for Simulation of Three-Dimensional Variable-Density Ground-Water Flow and Transport
SEAWAT is a combined version of MODFLOW and MT3DMS for simulation of variable-density groundwater flow and transport.
Groundwater Modeling Software MODFLOW 6 Now Available
MODFLOW 6, the newest version of the world’s most widely used groundwater modeling software, is now available for download from the U.S. Geological Survey