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Emanuel Weiss

Publications and source records attributed to Emanuel Weiss.

5 recordsLinked to original sources
USGS2010

Comparison of Darcian flow in corresponding flat and folded surfaces

F olds of aquifers are rarely accounted for in models of groundwater flow. To account for aquifer folds in groundwater flow models, the equation describing Darcian flow in a general surface is derived. The equation is used to calculate steady state hydraulic head distributions for corresponding folded and flat surfaces. Each flat surface has the same hydraulic conductivity distribution and boundary condition as the corresponding folded surface. The folded surfaces have folds similar to the folds of selected aquifers and have folds that have much larger changes in slope. The largest difference in hydraulic head caused by all folding is only about 0.5% of the largest difference in hydraulic head across each surface. Because of the smaller areal extent and the fact that the effect of a sequence of folds is not cumulative, the minor folds do not generate substantially larger hydraulic head differences than the major folds.

Water Resources Research↗
USGS1987

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)

Water-Resources Investigations Report↗
USGS1982

A model for the simulation of flow of variable-density ground water in three dimensions under steady-state conditions

A computer program has been developed as part of the U.S. Geological Survey's national program of Regional Aquifer System Analysis (RASA) that generates input to ground-water flow models to enable them to simulate variable-density ground-water flow. Information required for the program's operation is: aquifer elevation, thickness, and ground-water density. Included in the report is a computer program for calculating ground-water density from aquifer depth, temperature, and dissolved solids concentration. The 60-page report describes the theoretical development and documents two FORTRAN programs used to generate the necessary flow-model input. An example for a symmetrical basin is fully worked out.

Open-File Report↗
USGS1982

A computer program for calculating relative-transmissivity input arrays to aid model calibration

A program is documented that calculates a transmissivity distribution for input to a digital ground-water flow model. Factors that are taken into account in the calculation are: aquifer thickness, ground-water viscosity and its dependence on temperature and dissolved solids, and permeability and its dependence on overburden pressure. Other factors affecting ground-water flow are indicated. With small changes in the program code, leakance also could be calculated. The purpose of these calculations is to provide a physical basis for efficient calibration, and to extend rational transmissivity trends into areas where model calibration is insensitive to transmissivity values.

Open-File Report↗