Hydrogeology and simulation of ground-water and surface-water flow in Pinal Creek Basin, Gila County, Arizona

摘要

Acidic water with elevated concentrations of metals has contaminated a stream and alluvial aquifer in a mining district near Globe, Arizona. The contaminated aquifer is a narrow layer of unconsolidated alluvium along Miami Wash and Final Creek. The purpose of this study was to evaluate the hydrogeology of this area and to simulate the surface- and ground-water flow. The alluvium overlies basin fill which extends throughout most of Final Creek basin. Together, the alluvium and basin fill comprise the primary aquifer in the basin. Horizontal hydraulic conductivities have been estimated to be about 200 m/day in the alluvium, and average linear, ground-water flow velocities are on the order of 5 m/day. Flow was simulated by a three-dimensional, finite-difference, ground-water flow model that maintains a streamflow water budget. Steady-state simulations were performed and adjusted to represent average annual water budget conditions. The transient simulation period covers September 1984 to April 1989, for which considerable data were available for model calibration.