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
Use of hydrologic and hydrodynamic modeling for ecosystem restoration
Planning and implementation of unprecedented projects for restoring the greater Everglades ecosystem are underway and the hydrologic and hydrodynamic modeling of restoration alternatives has become essential for success of restoration efforts. In view of the complex nature of the South Florida water resources system, regional-scale (system-wide)...
Obeysekera, J.; Kuebler, L.; Ahmed, S.; Chang, M.-L.; Engel, V.; Langevin, Christian D.; Swain, Eric D.; Wan, Y. A comparison between SWI and SEAWAT: the importance of dispersion, inversion and vertical anisotropy
SWI and SEAWAT are both computer codes designed to model variable-density systems. One of the options in SWI is to model Dupuit interface flow, where freshwater and seawater are separated by an interface. In this paper we compare seawater intrusion model results of SWI to model results of SEAWAT, which simulates full variable-density flow and...
Dausman, Alyssa M.; Langevin, Christian D.; Bakker, Mark; Schaars, Frans Effect of sea-level rise on future coastal groundwater resources in southern Florida, USA
An existing variable‐density groundwater flow and solute transport model, developed for the northern part of Broward County, Florida, was used to predict the effect of sealevel rise on future coastal groundwater resources. Using average annual conditions from 2005, simulations were performed for 100 years into the future using four different rates...
Langevin, Christian D.; Zygnerski, Michael R.; White, Jeremy T.; Hughes, Joseph D. Creative use of pilot points to address site and regional scale heterogeneity in a variable-density model
Pilot points for parameter estimation were creatively used to address heterogeneity at both the well field and regional scales in a variable-density groundwater flow and solute transport model designed to test multiple hypotheses for upward migration of fresh effluent injected into a highly transmissive saline carbonate aquifer. Two sets of pilot...
Dausman, Alyssa M.; Doherty, John; Langevin, Christian D.
Application of SEAWAT to select variable-density and viscosity problems
SEAWAT is a combined version of MODFLOW and MT3DMS, designed to simulate three-dimensional, variable-density, saturated groundwater flow. The most recent version of the SEAWAT program, SEAWAT Version 4 (or SEAWAT_V4), supports equations of state for fluid density and viscosity. In SEAWAT_V4, fluid density can be calculated as a function of one or...
Dausman, Alyssa M.; Langevin, Christian D.; Thorne, Danny T.; Sukop, Michael C. Evaluating the effect of Tikhonov regularization schemes on predictions in a variable‐density groundwater model
Calibration of highly‐parameterized numerical models typically requires explicit Tikhonovtype regularization to stabilize the inversion process. This regularization can take the form of a preferred parameter values scheme or preferred relations between parameters, such as the preferred equality scheme. The resulting parameter distributions...
White, Jeremy T.; Langevin, Christian D.; Hughes, Joseph D. Use of time series and harmonic constituents of tidal propagation to enhance estimation of coastal aquifer heterogeneity
A synthetic two‐dimensional model of a horizontally and vertically heterogeneous confined coastal aquifer system, based on the Upper Floridan aquifer in south Florida, USA, subjected to constant recharge and a complex tidal signal was used to generate 15‐minute water‐level data at select locations over a 7‐day simulation period. ...
Hughes, Joseph D.; White, Jeremy T.; Langevin, Christian D. Effect of numerical dispersion as a source of structural noise in the calibration of a highly parameterized saltwater intrusion model
A model with a small amount of numerical dispersion was used to represent saltwater 7 intrusion in a homogeneous aquifer for a 10-year historical calibration period with one 8 groundwater withdrawal location followed by a 10-year prediction period with two groundwater 9 withdrawal locations. Time-varying groundwater concentrations at arbitrary...
Langevin, Christian D.; Hughes, Joseph D. Quantifying data worth toward reducing predictive uncertainty
The present study demonstrates a methodology for optimization of environmental data acquisition. Based on the premise that the worth of data increases in proportion to its ability to reduce the uncertainty of key model predictions, the methodology can be used to compare the worth of different data types, gathered at different locations within...
Dausman, A.M.; Doherty, J.; Langevin, C.D.; Sukop, M.C. Solute and heat transport model of the Henry and Hilleke laboratory experiment
SEAWAT is a coupled version of MODFLOW and MT3DMS designed to simulate variable-density ground water flow and solute transport. The most recent version of SEAWAT, called SEAWAT Version 4, includes new capabilities to represent simultaneous multispecies solute and heat transport. To test the new features in SEAWAT, the laboratory experiment of...
Langevin, C.D.; Dausman, A.M.; Sukop, M.C. Effect of hypersaline cooling canals on aquifer salinization
The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat...
Hughes, Joseph D.; Langevin, Christian D.; Brakefield-Goswami, Linzy
SEAWAT: A Computer Program for Simulation of Variable-Density Groundwater Flow and Multi-Species Solute and Heat Transport
SEAWAT is a MODFLOW-based computer program designed to simulate variable-density groundwater flow coupled with multi-species solute and heat transport. The program has been used for a wide variety of groundwater studies including saltwater intrusion in coastal aquifers, aquifer storage and recovery in brackish limestone aquifers, and brine...
Langevin, Christian D.