Ground-water flow in the Navajo sandstone in parts of Emery, Grand, Carbon, Wayne, Garfield, and Kane counties, southeast Utah

A finite-difference model of one layer was constructed to determine groundwater flow directions and magnitudes in the Navajo Sandstone of southeast Utah. Hydraulic head data, hydraulic conductivity data, precipitation data, and other data collected in the area were used in constructing and calibrating the model. Sensitivity of the model to unknown aspects of the groundwater system was investigated. Simulation error attributable to grid-size error was unexpectedly large, but compared to the uncertainty in the groundwater system, simulation error was not large. (USGS)