A Modular Three-Dimensional Finite-Difference Ground-Water Flow Model

By Michael G. McDonald and Arlen W. Harbaugh


TRANSLATED BY: Weixing Guo and Guoping Lu


We have an html version of the abstract and table of contents below.  The full report is available in pdf.  Links to the pdf.

picture of Chinese cover


picture of Chinese abstract



This report presents a finite-difference model and its associated modular computer program. The model simulates flow in three dimensions. The report includes detailed explanations of physical and mathematical concepts on which the model is based and an explanation of how those concepts are incorporated in the modular structure of the computer program. The modular structure consists of a Main Program and a series of highly independent subroutines called "modules." The modules are grouped into "packages." Each package deals with a specific feature of the hydrologic system which is to be simulated, such as flow from rivers or flow into drains, or with a specific method of solving linear equations which describe the flow system, such as the Strongly Implicit Procedure or Slice-Successive Overrelaxation.

The division of the program into modules permits the user to examine specific hydrologic features of the model independently. This also facilita development of additional capabilities because new packages can be added to the program without modifying the existing packages. The input and output systems of the computer program are also designed to permit maximum flexibility.

Ground-water flow within the aquifer is simulated using a block-centered finite-difference approach. Layers can be simulated as confined, unconfined, or a combination of confined and unconfined. Flow associated with external stresses, such as wells, areal recharge, evapotranspiration, drains, and streams, can also be simulated. The finite-difference equations can be solved using either the Strongly Implicit Procedure or Slice-Successive Overrelaxation.

The program is written in FORTRAN 77 and will run without modification on most computers that have a FORTRAN 77 compiler. For each program ,module, this report includes a narrative description, a flow chart, a list of variables, and a module listing.



Chapter 1. Introduction

Chapter 2. Derivation of the Finite-Difference Equation

Chapter 3. Program Design

Chapter 4. Basic Package

Chapter 5. Block-Centered Flow Package.

Chapter 6. River Package

Chapter 7. Recharge Package

Chapter 8. Well Package

Chapter 9. Drain Package

Chapter 10. Evapotranspiration Package

Chapter 11. General-Head Boundary Package

Chapter 12. Strongly Implicit Procedure Package

Chapter 13. Slice-Successive Overrelaxation Package

Chapter 14. Utility Modules


Appendix A--Program Portability

Appendix B-Space Requirements in the X Array

Appendix C--Continuation of a Previous Run

Appendix D--Sample Problem

Appendix E--Abbreviated Input Instructions


If you have Adobe Acrobat Reader installed on your computer, you may view and/or print the PDF version of this report. If you do not have Acrobat Reader, you may download it here.

The pdf file: TWRI Book 6, Chapter A1 (Chinese only) Full Report 7 MB)

For faster download you might want to download by chapters.

Contents and Chapter 1 (Chinese only) Full Report 605KB)

Chapter 2 (Chinese only) 2MB

Chapter 3 (Chinese only) 1MB

Chapter 4 (Chinese only) 474KB

Chapter 5 (Chinese only) 1MB

Chapters 6, 7, 8, 9, and 10(Chinese only) 1.1MB)

Chapters 11, 12, 13,and 14 (Chinese only) 1.2MB

References and Appendix (Chinese only) 633KB)


[an error occurred while processing this directive]
U.S. Department of the Interior, U.S. Geological Survey
Maintainer: Publications Team
Last update: 11:05:48 Thu 25 Jan 2001
Privacy Statement || Disclaimer
FirstGov, 'Your First Click to the U. S. Government'