Role of salinity-derived variable-density flow in the displacement of brine from a shallow, regionally extensive aquifer

摘要: Portions of many regional-scale aquifers in midcontinent sedimentary basins exhibit large salinity gradients that significantly impact the velocity field and solute distribution through time. A two-dimensional, numerical transport model was constructed to examine role salinity-derived variable-density flow on changes distributions a near-surface, regionally extensive aquifer as brine is displaced by infiltrating meteoric water. The Silurian-Devonian carbonate western portion Appalachian Basin used framework insure realistic velocities salinities were assessment. effects displacement are observed examining differences fields produced uniform-density simulations. include change from an intraformational pattern cross-formational with development reversals partitioning regional cells into smaller cells. Variable-density also manifest slowing influencing magnitude gradient. sensitivity analysis influence parameters transient migration shows increasing leakage causes decrease, which magnifies behavior brine. value dispersivity increase effects. However, relatively insensitive values horizontal vertical anisotropy assigned or presence overlying transmissive layer.