Stochastic-convective ensemble method for representing dispersive transport in groundwater
A stochastic-convective transport method is developed to describe three-dimensional hydrodispersion of a non-reactive solute in groundwater. The method is based on the probability density function (Pdf) for an ensemble model of stochastic variation in flow velocity. It is shown how the statistical parameters of a travel length Pdf are related to the mean and spatial covariance of a velocity field. Concepts of the method are demonstrated explicitly with a simple example tent-shaped Pdf. Linear increase of effective dispersivity with solute travel distance, when velocity correlation is long-range, is explained by the method. Previously derived results about macrodispersion in a stratified system (Materon and DeMarsily 1980) are obtained with an ensemble viewpoint and are generalized for non-uniform velocity. A scale-relation description of hydraulic conductivity and hydraulic gradient random variations is developed to represent stochastic velocity. That approach is based on a multiplicative rather than an additive stochastic process. It is shown that a covariance function for relative velocity variation, i.e., a ratio of random velocity to the mean, is perhaps a better description of random variations in porous media. The method is applied to a small-scale tracer experiment performed near the Borden landfill, Waterloo, Ontario. An indirect evaluation of stochastic transport parameters is demonstrated for the sandy aquifer site.
- Research Organization:
- Battelle Pacific Northwest Labs., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6844987
- Report Number(s):
- EPRI-CS-2558; ON: DE82021340
- Country of Publication:
- United States
- Language:
- English
Similar Records
Generalization of one-dimensional solute transport. A stochastic-convective flow conceptualization
Analysis of column tracer experiments by a stochastic-convective transport method
Related Subjects
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
DIFFUSION
ENVIRONMENTAL TRANSPORT
FLUID FLOW
GROUND WATER
HYDRAULIC CONDUCTIVITY
HYDROGEN COMPOUNDS
LIQUID FLOW
MASS TRANSFER
MATERIALS
MATHEMATICAL MODELS
OXYGEN COMPOUNDS
POROUS MATERIALS
SOLUTES
STOCHASTIC PROCESSES
SURFACE PROPERTIES
THREE-DIMENSIONAL CALCULATIONS
WATER