Dr. Christian Langevin is a research hydrologist with the USGS Water Resources Mission Area.
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.
MODFLOW 6 model of two hypothetical stream-aquifer systems to demonstrate the utility of the new Mover Package available only with MODFLOW 6
Two MODFLOW 6 (version 6.2.1) models of hypothetical stream-aquifer systems are presented for the demonstration and utility of the Water Mover (MVR) Package available only with MODFLOW 6. Using a generalized approach, MVR facilitates the transfer of water among many arbitrary combinations of simulated features (i.e., pumping wells, stream, drains, lakes, etc.) within a MODFLOW 6 simulation. In th
Filter Total Items: 65
Estimation of the water table position in unconfined aquifers with MODFLOW 6
The numerical estimation of the position of the water table in unconfined aquifers is important for many practical applications. Its determination through observations or analytical methods is restricted to a few cases. Therefore, it is often estimated through numerical simulations, which may be affected by numerical artifacts and/or poor stability. We use MODFLOW to estimate the position of the w
Improved method for simulating groundwater inundation using the MODFLOW 6 Lake Transport Package
Groundwater inundation due to sea level rise can affect island and coastal freshwater resources by exposing water tables to direct, continuous evaporation. Numerical simulations of groundwater inundation effects on coastal and island aquifers have been limited by an inability to simulate solute transport and variable density flow between the aquifer and lakes formed by groundwater inundation. Cons
Documentation for the MODFLOW 6 Groundwater Transport Model
This report documents a new Groundwater Transport (GWT) Model for MODFLOW 6. The GWT Model simulates three-dimensional transport of a single chemical species in fowing groundwater based on a generalized control-volume fnite-difference approach. Although each GWT Model is only able to represent a single chemical species, multiple GWT Models may be invoked within a single MODFLOW 6 simulation to rep
The MODFLOW Application Programming Interface for simulationcontrol and software interoperability
The MODFLOW API allows other programs to control MODFLOW and interactively change variables without having to modify the source code. The MODFLOW API is based on the Basic Model Interface (BMI), which is a set of conventions that define how to initialize a simulation, update the model state by advancing in time, and finalize the run. For many existing MODFLOW coupling applications, the information
Use of the MODFLOW 6 water mover package to represent natural and managed hydrologic connections
The latest release of MODFLOW 6, the current core version of the MODFLOW groundwater modeling software, debuted a new package dubbed the “mover” (MVR). Using a generalized approach, MVR facilitates the transfer of water among any arbitrary combination of simulated features (i.e., pumping wells, stream, drains, lakes, etc.) within a MODFLOW 6 simulation. Four “rules” controlling the amount of water
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, but results instead from upward migration of deep sal
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 packages, including (1) a structured discretization pac
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 the accuracy of groundwater-flow simulations in case
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, there are incompatibilities between these different M
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. Unsaturated-zone transport and transport within st
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, including packages for plotting, array manipulati
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 over large areas; this coarse spacing precludes mo
MODFLOW 6: USGS Modular Hydrologic Model
MODFLOW is a popular open-source groundwater flow model distributed by the U.S. Geological Survey.
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-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, unconfined, or a combination of confined and unconfined.
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.
Science and Products
- Science
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. - Data
MODFLOW 6 model of two hypothetical stream-aquifer systems to demonstrate the utility of the new Mover Package available only with MODFLOW 6
Two MODFLOW 6 (version 6.2.1) models of hypothetical stream-aquifer systems are presented for the demonstration and utility of the Water Mover (MVR) Package available only with MODFLOW 6. Using a generalized approach, MVR facilitates the transfer of water among many arbitrary combinations of simulated features (i.e., pumping wells, stream, drains, lakes, etc.) within a MODFLOW 6 simulation. In th - Publications
Filter Total Items: 65
Estimation of the water table position in unconfined aquifers with MODFLOW 6
The numerical estimation of the position of the water table in unconfined aquifers is important for many practical applications. Its determination through observations or analytical methods is restricted to a few cases. Therefore, it is often estimated through numerical simulations, which may be affected by numerical artifacts and/or poor stability. We use MODFLOW to estimate the position of the wImproved method for simulating groundwater inundation using the MODFLOW 6 Lake Transport Package
Groundwater inundation due to sea level rise can affect island and coastal freshwater resources by exposing water tables to direct, continuous evaporation. Numerical simulations of groundwater inundation effects on coastal and island aquifers have been limited by an inability to simulate solute transport and variable density flow between the aquifer and lakes formed by groundwater inundation. ConsDocumentation for the MODFLOW 6 Groundwater Transport Model
This report documents a new Groundwater Transport (GWT) Model for MODFLOW 6. The GWT Model simulates three-dimensional transport of a single chemical species in fowing groundwater based on a generalized control-volume fnite-difference approach. Although each GWT Model is only able to represent a single chemical species, multiple GWT Models may be invoked within a single MODFLOW 6 simulation to repThe MODFLOW Application Programming Interface for simulationcontrol and software interoperability
The MODFLOW API allows other programs to control MODFLOW and interactively change variables without having to modify the source code. The MODFLOW API is based on the Basic Model Interface (BMI), which is a set of conventions that define how to initialize a simulation, update the model state by advancing in time, and finalize the run. For many existing MODFLOW coupling applications, the informationUse of the MODFLOW 6 water mover package to represent natural and managed hydrologic connections
The latest release of MODFLOW 6, the current core version of the MODFLOW groundwater modeling software, debuted a new package dubbed the “mover” (MVR). Using a generalized approach, MVR facilitates the transfer of water among any arbitrary combination of simulated features (i.e., pumping wells, stream, drains, lakes, etc.) within a MODFLOW 6 simulation. Four “rules” controlling the amount of waterRebuttal 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, but results instead from upward migration of deep salDocumentation 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 packages, including (1) a structured discretization pacDocumentation 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 the accuracy of groundwater-flow simulations in caseDocumentation 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, there are incompatibilities between these different MMT3D-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. Unsaturated-zone transport and transport within stScripting 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, including packages for plotting, array manipulatiA 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 over large areas; this coarse spacing precludes mo - Software
MODFLOW 6: USGS Modular Hydrologic Model
MODFLOW is a popular open-source groundwater flow model distributed by the U.S. Geological Survey.
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-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, unconfined, or a combination of confined and unconfined.
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.
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