Clifford I Voss, Ph.D.
Dr. Clifford Voss is a USGS Emeritus Scientist with the Water Resources Mission Area with over 40 years of project management, implementation, field and research experience in groundwater systems.
Dr. Clifford Voss is a USGS Emeritus Scientist with over 40 years of project management, implementation, field and research experience in groundwater systems. He deals with theoretical, field and practical issues in quantitative hydrogeology including: physics of subsurface fluids, computer model development and application to scientific evaluation of hydrogeologic systems, groundwater resources development and protection, coastal/island groundwater resources, subsurface energy production/storage, subsurface waste isolation, and cold-regions hydrology.
Dr. Voss is recognized as an international expert on groundwater modeling. He consults extensively on groundwater system evaluation and management, and lectures internationally on these and related subjects. The practical methodology and codes that Voss and his colleagues have developed (SUTRA and SutraSuite) are in standard use worldwide in subsurface assessment, aiding in quantity-quality management of groundwater resources and in evaluation of human impacts on the subsurface environment. These codes also allow development of a deeper understanding of important hydrogeologic processes.
His current interests involve: subsurface flow/transport in heterogeneous hydrogeologic media, cold-regions hydrology, development and application of practical methodology and subsurface hydrology simulation codes (SUTRA and SutraSuite) with freeze/thaw for study of ground-ice and permafrost in cold regions and associated code-benchmark development, flow and transport in variable-density subsurface fluids (seawater, brine, hot/cold groundwater), inverse modeling, network design, optimization of groundwater management, use of isotopes in characterizing subsurface systems, and the climate/ecology/society/water nexus.
Dr. Voss has conducted many crucial subsurface resource understanding and management studies, including: nuclear waste repository siting safety and performance (Sweden, Germany, Japan), coastal aquifer and seawater intrusion management (Hawaii USA, other USA, and worldwide), transboundary aquifer management (Nubian Aquifer of Egypt, Libya, Chad, Sudan); sustainability of arsenic-free groundwater supply (Bengal Delta Aquifer of India, Bangladesh); discovering the dynamics of cold-regions hydrologic systems (Canada, China, Greenland/Denmark, Sweden, USA).
Dr. Voss is Executive Editor of "Hydrogeology Journal" the official journal of the International Association of Hydrogeologists (since 1994).
Science and Products
Conceptual uncertainty in crystalline bedrock: Is simple evaluation the only practical approach?
Dynamics of a regional freshwater-saltwater transition zone in an anisotropic coastal aquifer system
Glaciation and regional ground-water flow in the Fennoscandian Shield: Site 94
A Graphical-User Interface for the U. S. Geological Survey's SUTRA Code using Argus ONE (for simulation of variable-density saturated-unsaturated ground-water flow with solute or energy transport)
Regional flow in the Baltic Shield during Holocene coastal regression
Sampling design for groundwater solute transport: Tests of methods and analysis of Cape Cod tracer test data
Multiobjective sampling design for parameter estimation and model discrimination in groundwater solute transport
Further comments on sensitivities, parameter estimation, and sampling design in one-dimensional analysis of solute transport in porous media
Behavior of sensitivities in the one-dimensional advection-dispersion equation: Implications for parameter estimation and sampling design
Solute transport with equilibrium aqueous complexation and either sorption or ion exchange: Simulation methodology and applications
Aquifer reclamation design: The use of contaminant transport simulation combined with nonlinear programing
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Conceptual uncertainty in crystalline bedrock: Is simple evaluation the only practical approach?
A simple evaluation can be used to characterise the capacity of crystalline bedrock to act as a barrier to releases of radionuclides from a nuclear waste repository. Physically plausible bounds on groundwater flow and an effective transport-resistance parameter are estimated based on fundamental principles and idealised models of pore geometry. Application to an intensively characterised site in SAuthorsJ. Geier, C.I. Voss, B. DverstorpDynamics of a regional freshwater-saltwater transition zone in an anisotropic coastal aquifer system
No abstract available.AuthorsClifford I. Voss, William R. SouzaGlaciation and regional ground-water flow in the Fennoscandian Shield: Site 94
Results from a regional-scale ground-water flow model of the Fennoscandian shield suggest that ground-water flow is strongly affected by surface conditions associated with climatic change and glaciation. The model was used to run a series of numerical simulations of variable-density ground-water flow in a 1500-km-long and approximately 10-km-deep cross-section that passes through southern SwedAuthorsAlden M. Provost, Clifford I. Voss, C. E. NeuzilA Graphical-User Interface for the U. S. Geological Survey's SUTRA Code using Argus ONE (for simulation of variable-density saturated-unsaturated ground-water flow with solute or energy transport)
This report describes a Graphical-User Interface (GUI) for SUTRA, the U.S. Geological Survey (USGS) model for saturated-unsaturated variable-fluid-density ground-water flow with solute or energy transport,which combines a USGS-developed code that interfaces SUTRA with Argus ONE, a commercial software product developed by Argus Interware. This product, known as Argus Open Numerical Environments (ArAuthorsClifford I. Voss, David Boldt, Allen M. ShapiroRegional flow in the Baltic Shield during Holocene coastal regression
The occurrence of saline waters in the Baltic Shield in Sweden is consistent with ongoing but incomplete Holocene flushing and depends on the geometry and connectivity of conductive structures at both regional and local scales, and on the surface topography. Numerical simulation of regional variable-density fluid flow during Holocene land-rise and coastal regression shows that the existence of anyAuthorsClifford I. Voss, Johan AnderssonSampling design for groundwater solute transport: Tests of methods and analysis of Cape Cod tracer test data
Tests of a one-dimensional sampling design methodology on measurements of bromide concentration collected during the natural gradient tracer test conducted by the U.S. Geological Survey on Cape Cod, Massachusetts, demonstrate its efficacy for field studies of solute transport in groundwater and the utility of one-dimensional analysis. The methodology was applied to design of sparse two-dimensionalAuthorsDebra S. Knopman, Clifford I. Voss, Stephen P. GarabedianMultiobjective sampling design for parameter estimation and model discrimination in groundwater solute transport
Sampling design for site characterization studies of solute transport in porous media is formulated as a multiobjective problem. Optimal design of a sampling network is a sequential process in which the next phase of sampling is designed on the basis of all available physical knowledge of the system. Three objectives are considered: model discrimination, parameter estimation, and cost minimizationAuthorsDebra S. Knopman, Clifford I. VossFurther comments on sensitivities, parameter estimation, and sampling design in one-dimensional analysis of solute transport in porous media
Sensitivities of solute concentration to parameters associated with first-order chemical decay, boundary conditions, initial conditions, and multilayer transport are examined in one-dimensional analytical models of transient solute transport in porous media. A sensitivity is a change in solute concentration resulting from a change in a model parameter. Sensitivity analysis is important because minAuthorsDebra S. Knopman, Clifford I. VossBehavior of sensitivities in the one-dimensional advection-dispersion equation: Implications for parameter estimation and sampling design
The spatial and temporal variability of sensitivities has a significant impact on parameter estimation and sampling design for studies of solute transport in porous media. Physical insight into the behavior of sensitivities is offered through an analysis of analytically derived sensitivities for the one-dimensional form of the advection-dispersion equation. When parameters are estimated in regressAuthorsDebra S. Knopman, Clifford I. VossSolute transport with equilibrium aqueous complexation and either sorption or ion exchange: Simulation methodology and applications
Methodologies that account for specific types of chemical reactions in the simulation of solute transport can be developed so they are compatible with solution algorithms employed in existing transport codes. This enables the simulation of reactive transport in complex multidimensional flow regimes, and provides a means for existing codes to account for some of the fundamental chemical processes tAuthorsF.M. Lewis, Clifford I. Voss, J. RubinAquifer reclamation design: The use of contaminant transport simulation combined with nonlinear programing
A simulation-management methodology is demonstrated for the rehabilitation of aquifers that have been subjected to chemical contamination. Finite element groundwater flow and contaminant transport simulation are combined with nonlinear optimization. The model is capable of determining well locations plus pumping and injection rates for groundwater quality control. Examples demonstrate linear or noAuthorsSteven M. Gorelick, Clifford I. Voss, Philip E. Gill, Walter Murray, Michael A. Saunders, Margaret H. Wright - Software