Premium
Finite‐Element Simulation of Long‐Term Transient Regional Ground‐Water Flow
Author(s) -
England Lindy A.,
Freeze R. Allan
Publication year - 1988
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1988.tb00393.x
Subject(s) - hydraulic conductivity , geology , hydraulic head , sedimentary rock , permeability (electromagnetism) , geotechnical engineering , plume , head (geology) , finite element method , groundwater , subsurface flow , soil science , geomorphology , hydrology (agriculture) , petrology , geochemistry , engineering , genetics , physics , membrane , biology , soil water , thermodynamics , structural engineering
A finite‐element model is developed to solve the two‐dimensional, transient, ground‐water flow equation on a regional scale over geologic time for the purpose of assessing the rate of hydraulic head decay at depth in response to erosional modifications of the land surface. The model includes a time‐stepping procedure that allows consideration of sedimentary basins with large hydraulic conductivity contrasts. Results confirm that hydraulic head patterns that are not in equilibrium with existing topography can persist at depth over geologically significant periods of time. A sensitivity analysis on a hypothetical layered system shows that the rate of hydraulic head adjustment, due to erosional modifications of the topography, is particularly sensitive to the thickness, continuity, and vertical hydraulic conductivity of the low‐permeability layers. Application of the two‐dimensional model to the Red earth region of northern Alberta, Canada predicts response times that are reduced by two‐thirds over those predicted with one‐dimensional models. The concept of delayed hydraulic response over geologic time has important implications in the siting and design of nuclear waste repositories, the analysis of contaminant plume migration, and the use of the hydrodynamic approach to the exploration for petroleum resources and stratabound ore deposits.