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Naval Support Activity (NSA) Memphis is a Department of the Navy facility located at the City of Millington, Tennessee, about 5 miles north of Memphis. Contaminants have been detected in surface-water, sediment, and ground-water samples collected at the facility. As part of the Installation Restoration Program, the Navy is considering...

A computer program called the Flow and Head Boundary Package (FHB1) was developed for the U.S. Geological Survey three-dimensional finite-difference modular ground-water flow model, commonly referred to as MODFLOW. FHB1 allows MODFLOW users to specify flow or head boundary conditions that vary at times other than starting and ending times...

Increasing population and associated residential and commercial development have greatly increased water use and consumption in the Verde Valley near Montezuma Well, a unit of Montezuma Castle National Monument in central Arizona. Flow from Montezuma Well and water levels in eight wells that are measured annually do not indicate that...

MODTOOLS is a set of computer programs for translating data of the ground-water model, MODFLOW, and the particle-tracker, MODPATH, into a Geographic Information System (GIS). MODTOOLS translates data into a GIS software called ARC/INFO. MODFLOW is the recognized name for the U.S. Geological Survey Modular Three-Dimensional Finite-Difference Ground-Water Model. MODTOOLS...

A comparison between two hypothetical flow models of an unconfined aquifer, one saturated and the other variably saturated, indicates that the variably saturated model which explicitly models drainage from the unsaturated zone provides a better conceptual framework for analyzing unconfined aquifer test data and better estimates of the lateral and...

Leakage to ground water resulting from the expansion and contraction of reservoirs cannot be easily simulated by most ground-water flow models. An algorithm, entitled the Reservoir Package, was developed for the United States Geological Survey (USGS) three-dimensional finite-difference modular ground-water flow model MODFLOW. The Reservoir...

This report presents a model, MOC3D, that simulates three-dimensional solute transport in flowing ground water. The model computes changes in concentration of a single dissolved chemical constituent over time that are caused by advective transport, hydrodynamic dispersion (including both mechanical dispersion and diffusion), mixing (or dilution) from fluid sources, and...

MODFLOW and MODPATH numerical models were used to generate areas of contribution to public supply wells for simulated hypothetical anisotropy and heterogeneous carbonate aquifer systems. The simulations incorporated, to varying degrees, the anisotropy and heterogeneity observed in a karst carbonate aquifer system. These include: isotropic and homogeneous single-layer system, doubly-porous...

A technique has been developed to determine a wetlands hydroperiod by comparing simulated water levels from a ground-water flow model and land- surface elevation data through a geographic information system. The simulated water levels are compared with the land-surface elevation data to determine the height of the water surface above...

A coupled surface-water model (BRANCH) and ground-water model (MODFLOW) model were tested to simulate the interacting wetlands/surface-water/ ground-water system of southern Dade County. Several options created for the MODFLOW ground- ground-water model were used in representing this field situation. The primary option is the MODBRANCH interfacing software, which allows leakage...

Large chloride concentrations in Arkansas River water have the potential to degrade water quality in the adjacent Equus beds aquifer between Hutchinson and Wichita, Kansas. The aquifer is an important source of water for municipal, industrial, agricultural, and domestic uses. A three-dimensional, finite-difference, ground-water flow-model program (MODFLOW) was used with...

Ground-water and surface-water flow models traditionally have been developed separately, with interaction between subsurface flow and streamflow either not simulated at all or accounted for by simple formulations. In areas with dynamic and hydraulically well-connected ground-water and surface-water systems, stream-aquifer interaction should be simulated using deterministic responses of both systems...

Nonlinear regression is useful in ground-water flow parameter estimation, but problems of parameter insensitivity and correlation often exist given commonly available hydraulic-head and head-dependent flow (for example, stream and lake gain or loss) observations. To address this problem, advective-transport observations are added to the ground-water flow, parameter-estimation model MODFLOWP using...

A practical approach to modeling the hydraulic interaction of a stream and aquifer via streambed leakage is based on the established U.S. Geological Survey (USGS) model, MODFLOW. To represent flood-wave propagation and the associated bank storage, MODFLOW's STREAM module is replaced by the Muskingum-Cunge diffusive-wave-routing scheme. The diffusive wave model...

Estimation of unrealistic parameter values by inverse modelling is useful for constructed model discrimination. This utility is demonstrated using the three-dimensional, groundwater flow inverse model MODFLOWP to estimate parameters in a simple synthetic model where the true conditions and character of the errors are completely known. When a poorly constructed...

The hdpw (head-in-a-pumping-well) program described in this report is a post-processor that calculates the head in a pumping well based on thesimulated head at a finite-difference model cell that contains the well. The calculations are based on the Thiem equation. The hdpw code works with the U.S....

This report contains MODFLOW input and output listings for the simulation of ground-water flow in alluvium and terrace deposits associated with the Cimarron River from Freedom to Guthrie, Oklahoma. These values are to be used in conjuction with the report, 'Geohydrology of alluvium and terrace deposits of the Cimarron River...

No abstract available....

The Eutaw-McShan aquifer and Tuscaloosa aquifer system in northeastern Mississippi were investi- gated to better understand the hydrogeology and the ground-water flow in and between the aquifers. A numerical model was developed to simulate ground- water flow for prepumping and pumping conditions, and model simulatons projected the possible effects of...