A method of converting no-flow cells to variable-head cells for the U. S. Geological Survey modular finite-difference ground-water flow model
TLDR
The U.S. Geological Survey Modular Ground-Water Flow Model (MODFLOW) as mentioned in this paper simulates ground-water flow through porous media using the finite-difference method.Abstract:
The U.S. Geological Survey Modular Ground-Water Flow Model, commonly referred to as MODFLOW, simulates ground-water flow through porous media using the finite-difference method. The region being modeled is divided into a grid of cells, and each cell is defined to be either no-flow, variable-head, or constant-head. The model calculates a value for head at all variable-head cells whereas head at constant-head cells is specified by the user. Cells are designated as no-flow cells if they contain impermeable material or are unsaturated, and accordingly the flow of water is not simulated in such cells. As originally published, MODFLOW could simulate the desaturation of variable-head model cells, which resulted in their conversion to no-flow cells, but could not simulate the resaturation of cells. That is, a no-flow cell could not be converted to variable head. However, such conversion is desirable in many situations. For example, one might wish to simulate pumping that desaturates some cells followed by the recovery of water levels after pumping is stopped. An option that allows cells to convert from noflow to variable-head has been added to the model. In this option, a cell is converted to variable head based on the head at neighboring cells. The option is written in FORTRAN 77 and is fully compatible with the existing model. This report documents the new option, including a description of the concepts, detailed input instructions, and a listing of the code. Example problems illustrate the practical applications of the option. Although solution of the modified flow equations can be difficult for the model solvers, the example problems show that it is possible to solve a variety of complex problems.read more
Citations
More filters
OtherDOI
MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model - User Guide to Modularization Concepts and the Ground-Water Flow Process
TL;DR: In this paper, the authors propose a method to solve the problem of homonymity in homonym identification, i.e., homonym-of-individuals-with-groups.
OtherDOI
MODFLOW-2005 : the U.S. Geological Survey modular ground-water model--the ground-water flow process
TL;DR: In this article, the authors propose a novel approach to solve the problem of homonymity in homophily, and propose a solution to the problem: homophysphysics.
OtherDOI
User's documentation for MODFLOW-96, an update to the U.S. Geological Survey modular finite-difference ground-water flow model
A.W. Harbaugh,M.G. McDonald +1 more
TL;DR: Budget calculations have been changed to double precision, which improves the accuracy of budget calculations, and new options have been added such as the ability to save calculated heads in formatted files and save budget data in more compact unformatted files.
OtherDOI
User's guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow
TL;DR: This chapter discusses the design and structure of the SEAWAT Program, and discusses Darcy’s Law in Terms of Equivalent Freshwater Head, as well as other aspects of variable-Density flow mechanics.
Journal ArticleDOI
Seasonal and storm dynamics of the hyporheic zone of a 4th-order mountain stream. I: Hydrologic processes
TL;DR: The overall pattern of subsurface flow changed little over the course of the year, even though the relative flux of advected channel water and ground water changed among seasons and during storms.
References
More filters
OtherDOI
A modular three-dimensional finite-difference ground-water flow model
TL;DR: A computer program for simulating ground-water flow in three dimensions by using a block-centered finite-difference approach and has a modular structure, which permits the addition of new packages to the program without modifying existing packages.
ReportDOI
PRECONDITIONED CONJUGATE-GRADIENT 2 (PCG2), a computer program for solving ground-water flow equations
ReportDOI
Computer program for solving ground-water flow equations by the preconditioned conjugate gradient method
TL;DR: This report documents a numerical code for use with the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model that uses the preconditioned conjugate gradient method for the solution of the finite difference approximating equations generated by the modular flow model.