Heterogeneity effects on flow and transport within a shallow fluvial aquifer

The effects of aquifer heterogeneity on flow and transport are considered numerically at two scales using high resolution groundwater models. Heterogeneity effects on river loss were evaluated at the kilometer scale using stochastic, geostatistical models with grid cells on the order of several meters. It was found that river loss decreased directly with an increase in the extent of heterogeneity and that homogeneous approximations resulted in increased loss estimates. Heterogeneity effects on transport were simulated at the scale of several meters using a homogeneous approximation, traditional geostatistical models and a new integrated method of aquifer characterization. The integrated method combines geophysics and geostatistics to create a more realistic approximation of subsurface features. Using grid cells of several centimeters, transport was simulated for multiple heterogeneity realizations in three directions through the models to evaluate potential anisotropy of the transport rates. The resulting breakthrough curves for the homogeneous and traditional geostatistical models showed no directional anisotropy but the integrated models showed anisotropic behavior consistent with the bedding direction as well as non-Fickian transport rates.

Name thesis:degree_name

Earth and Planetary Sciences

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Department of Earth and Planetary Sciences

Year

2009

Author dc:creator

• Engdahl, Nicholas

Contributors dc:contributor

• Weissmann, Gary
• Meyer, Grant
• Thomson, Bruce

• Heterogeneity
• Groundwater modeling

Language dc:language

English

Identifier

https://digitalrepository.unm.edu/eps_etds/27

OAI identifier oai:identifier

oai:digitalrepository.unm.edu:eps_etds-1026