Christian Langevin (Former Employee)
Science and Products
Filter Total Items: 71
An autonomous, electromagnetic seepage meter to study coastal groundwater/surface-water exchange An autonomous, electromagnetic seepage meter to study coastal groundwater/surface-water exchange
The bi-directional exchange of groundwater with coastal surface waters may influence not only coastal-water and geochemical budgets, but may also impact and direct coastal ecosystem change. For example, the widespread discharge of nutrient-enriched submarine groundwater into an estuary or lagoon may contribute directly to the onset and duration of eutrophication, as well as the...
Authors
Peter W. Swarzenski, Matt Charette, Christian D. Langevin
Development of coastal flow and transport models in support of everglades restoration Development of coastal flow and transport models in support of everglades restoration
No abstract available.
Authors
Christian D. Langevin, Eric D. Swain, John D. Wang, Melinda A. Wolfert, Raymond W. Schaffranek, Ami L. Riscassi
Simulation of Integrated Surface-Water/Ground-Water Flow and Salinity for a Coastal Wetland and Adjacent Estuary Simulation of Integrated Surface-Water/Ground-Water Flow and Salinity for a Coastal Wetland and Adjacent Estuary
The SWIFT2D surface-water flow and transport code, which solves the St. Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. The integrated code was applied to the southern Everglades of Florida to quantify flow and salinity patterns and to evaluate effects of...
Authors
Christian D. Langevin, Eric D. Swain, Wolfert Melinda A.
The rotating movement of three immiscible fluids - A benchmark problem The rotating movement of three immiscible fluids - A benchmark problem
A benchmark problem involving the rotating movement of three immiscible fluids is proposed for verifying the density-dependent flow component of groundwater flow codes. The problem consists of a two-dimensional strip in the vertical plane filled with three fluids of different densities separated by interfaces. Initially, the interfaces between the fluids make a 45??angle with the...
Authors
M. Bakker, Essink G.H.P. Oude, C.D. Langevin
Stochastic Ground Water Flow Simulation with a Fracture Zone Continuum Model Stochastic Ground Water Flow Simulation with a Fracture Zone Continuum Model
A method is presented for incorporating the hydraulic effects of vertical fracture zones into two-dimensional cell-based continuum models of ground water flow and particle tracking. High hydraulic conductivity features are used in the model to represent fracture zones. For fracture zones that are not coincident with model rows or columns, an adjustment is required for the hydraulic...
Authors
C.D. Langevin
Simulation of Submarine Ground Water Discharge to a Marine Estuary: Biscayne Bay, Florida Simulation of Submarine Ground Water Discharge to a Marine Estuary: Biscayne Bay, Florida
Variable density ground water flow models are rarely used to estimate submarine ground water discharge because of limitations in computer speed, data availability, and availability of a simulation tool that can minimize numerical dispersion. This paper presents an application of the SEAWAT code, which is a combined version of MODFLOW and MT3D, to estimate rates of submarine ground water...
Authors
C.D. Langevin
MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT) MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT)
SEAWAT-2000 is the latest release of the SEAWAT computer program for simulation of three-dimensional, variable-density, transient ground-water flow in porous media. SEAWAT-2000 was designed by combining a modified version of MODFLOW-2000 and MT3DMS into a single computer program. The code was developed using the MODFLOW-2000 concept of a process, which is defined as ?part of the code...
Authors
Christian D. Langevin, W. Barclay Shoemaker, Weixing Guo
User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow
This report documents a computer program (SEAWAT) that simulates variable-density, transient, ground-water flow in three dimensions. The source code for SEAWAT was developed by combining MODFLOW and MT3DMS into a single program that solves the coupled flow and solute-transport equations. The SEAWAT code follows a modular structure, and thus, new capabilities can be added with only minor
Authors
Weixing Guo, C.D. Langevin
User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow
This report has been superceded by TWRI Book 6, Chapter A7
Authors
Weixing Guo, C.D. Langevin
Simulation of ground-water discharge to Biscayne Bay, southeastern Florida Simulation of ground-water discharge to Biscayne Bay, southeastern Florida
As part of the Place-Based Studies Program, the U.S. Geological Survey initiated a project in 1996, in cooperation with the U.S. Army Corps of Engineers, to quantify the rates and patterns of submarine ground-water discharge to Biscayne Bay. Project objectives were achieved through field investigations at three sites (Coconut Grove, Deering Estate, and Mowry Canal) along the coastline of...
Authors
Christian D. Langevin
Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system
A numerical ground water flow model was created in 1978 and revised in 1981 to predict the drawdown effects of a proposed municipal wellfield permitted to withdraw 30 million gallons per day (mgd; 1.1 × 105 m3/day) of water from the semiconfined Floridan Aquifer system. The predictions are based on the assumption that water levels in the semiconfined Floridan Aquifer reach a long-term...
Authors
M. Stewart, C. Langevin
Science and Products
Filter Total Items: 71
An autonomous, electromagnetic seepage meter to study coastal groundwater/surface-water exchange An autonomous, electromagnetic seepage meter to study coastal groundwater/surface-water exchange
The bi-directional exchange of groundwater with coastal surface waters may influence not only coastal-water and geochemical budgets, but may also impact and direct coastal ecosystem change. For example, the widespread discharge of nutrient-enriched submarine groundwater into an estuary or lagoon may contribute directly to the onset and duration of eutrophication, as well as the...
Authors
Peter W. Swarzenski, Matt Charette, Christian D. Langevin
Development of coastal flow and transport models in support of everglades restoration Development of coastal flow and transport models in support of everglades restoration
No abstract available.
Authors
Christian D. Langevin, Eric D. Swain, John D. Wang, Melinda A. Wolfert, Raymond W. Schaffranek, Ami L. Riscassi
Simulation of Integrated Surface-Water/Ground-Water Flow and Salinity for a Coastal Wetland and Adjacent Estuary Simulation of Integrated Surface-Water/Ground-Water Flow and Salinity for a Coastal Wetland and Adjacent Estuary
The SWIFT2D surface-water flow and transport code, which solves the St. Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. The integrated code was applied to the southern Everglades of Florida to quantify flow and salinity patterns and to evaluate effects of...
Authors
Christian D. Langevin, Eric D. Swain, Wolfert Melinda A.
The rotating movement of three immiscible fluids - A benchmark problem The rotating movement of three immiscible fluids - A benchmark problem
A benchmark problem involving the rotating movement of three immiscible fluids is proposed for verifying the density-dependent flow component of groundwater flow codes. The problem consists of a two-dimensional strip in the vertical plane filled with three fluids of different densities separated by interfaces. Initially, the interfaces between the fluids make a 45??angle with the...
Authors
M. Bakker, Essink G.H.P. Oude, C.D. Langevin
Stochastic Ground Water Flow Simulation with a Fracture Zone Continuum Model Stochastic Ground Water Flow Simulation with a Fracture Zone Continuum Model
A method is presented for incorporating the hydraulic effects of vertical fracture zones into two-dimensional cell-based continuum models of ground water flow and particle tracking. High hydraulic conductivity features are used in the model to represent fracture zones. For fracture zones that are not coincident with model rows or columns, an adjustment is required for the hydraulic...
Authors
C.D. Langevin
Simulation of Submarine Ground Water Discharge to a Marine Estuary: Biscayne Bay, Florida Simulation of Submarine Ground Water Discharge to a Marine Estuary: Biscayne Bay, Florida
Variable density ground water flow models are rarely used to estimate submarine ground water discharge because of limitations in computer speed, data availability, and availability of a simulation tool that can minimize numerical dispersion. This paper presents an application of the SEAWAT code, which is a combined version of MODFLOW and MT3D, to estimate rates of submarine ground water...
Authors
C.D. Langevin
MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT) MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT)
SEAWAT-2000 is the latest release of the SEAWAT computer program for simulation of three-dimensional, variable-density, transient ground-water flow in porous media. SEAWAT-2000 was designed by combining a modified version of MODFLOW-2000 and MT3DMS into a single computer program. The code was developed using the MODFLOW-2000 concept of a process, which is defined as ?part of the code...
Authors
Christian D. Langevin, W. Barclay Shoemaker, Weixing Guo
User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow
This report documents a computer program (SEAWAT) that simulates variable-density, transient, ground-water flow in three dimensions. The source code for SEAWAT was developed by combining MODFLOW and MT3DMS into a single program that solves the coupled flow and solute-transport equations. The SEAWAT code follows a modular structure, and thus, new capabilities can be added with only minor
Authors
Weixing Guo, C.D. Langevin
User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow
This report has been superceded by TWRI Book 6, Chapter A7
Authors
Weixing Guo, C.D. Langevin
Simulation of ground-water discharge to Biscayne Bay, southeastern Florida Simulation of ground-water discharge to Biscayne Bay, southeastern Florida
As part of the Place-Based Studies Program, the U.S. Geological Survey initiated a project in 1996, in cooperation with the U.S. Army Corps of Engineers, to quantify the rates and patterns of submarine ground-water discharge to Biscayne Bay. Project objectives were achieved through field investigations at three sites (Coconut Grove, Deering Estate, and Mowry Canal) along the coastline of...
Authors
Christian D. Langevin
Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system
A numerical ground water flow model was created in 1978 and revised in 1981 to predict the drawdown effects of a proposed municipal wellfield permitted to withdraw 30 million gallons per day (mgd; 1.1 × 105 m3/day) of water from the semiconfined Floridan Aquifer system. The predictions are based on the assumption that water levels in the semiconfined Floridan Aquifer reach a long-term...
Authors
M. Stewart, C. Langevin