Microcomputer Programs for Groundwater StudiesBy
- D. Clarke, Crystal Brook, S.A., Australia
This book provides the practising hydrogeologist with a selection of microcomputer programs which the author has found to be very useful as an aid in the investigation of groundwater wells and aquifers. The programs are written in BASIC and are designed to suit as wide a range of computer as possible.The book begins with a group of programs which solve several of the most common functions encountered in groundwater science. These are then developed into programs capable of calculating drawdown in a variety of discharge rate/aquifer/boundary configurations, either at one time, or a series of exponentially increasing times. The author shows how a computerised form of Newtons method (for solving difficult equations) may be applied to such tasks as evaluating storage coefficient if transmissivity is known. Lagrangian interpolation is used to produce accurate values from tabled functions, either within a program, or on demand.One of the major programs in the book may be used to enter discharge test data into a computer, edit it as required (e.g. change drawdown measurements from feet to metres, or water levels to drawdowns etc.), and finally to analyse the data. For example, three different methods are provided for evaluation of the well equation. Another program is provided for controlling a plotter to produce several popular types of discharge test graphs; and a new image well method is included for simulating boundaries consisting of straight line junctions between areas of two different transmissivities.This is a practical book, written to solve real-life problems. Accordingly, program operation is clearly described, but derivation of equations and functions have been omitted. (For those readers wishing to check on derivations, references are provided). Readers familiar with microcomputer programming may apply the programs given here to their own work, perhaps incorporating them as subroutines into large, more specialized programs. Those unfamiliar with programming can use the programs as they are listed. All programs are designed to be run with no more than an occasional reference to the written instructions being necessary.
Developments in Water Science
Published: June 1987
David Clarke's book ... is an important and timely contribution to this trend.
Journal of Ground Water
- Contents: Introduction. 1. Functions. The Well Function. The Modified Bessel Functions. The Leaky Artesian Well Function. Stirlings Approximation of the Factorial Function. The Gaussian Error Function and its Compliment. References. Program Listings. 2. Calculation of Drawdown. Drawdown in a Confined Aquifer. Drawdown in a Leaky Confined Aquifer. Drawdown in an Aquifer Bounded on One Side. Drawdown in a Leaky Confined, Bounded Aquifer. A Strip Aquifer. Drawdown in a Strip Aquifer. Drawdown in a Leaky Confined Strip Aquifer. References. Program Listings. 3. Evaluation of Storage Coefficient by Solution of the Well Equation. Newtons Method. Solution of the Theis Equation for Storage. References. Program Listings. 4. Simulation of Discharge Tests. A Multi-Stage Discharge Test in a Confined Aquifer. A Discharge Test in a Leaky Confined Aquifer. A Discharge Test in a Confined, Bounded, Aquifer. A Discharge Test in a Bounded, Leaky Confined Aquifer. A Discharge Test in a Confined Strip Aquifer. A Discharge Test in a Leaky Confined Strip Aquifer. Drawdown in a Pumped Well in a Confined Aquifer. Usage of Variables in the SIM Programs. Program Listings. 5. Interpolation. Methods of Interpolation. Program Lagrange. Program INTERP1. Program INTERP2. Reference. Program Listings. 6. Discharge Test Data Handling and Analysis. Functions of Program DTDHA. Overall Program Structure. Unprogrammed Modification of Data. Running the Program. Menu 1: The Main Menu. Menu 2: Data Modification. Menu 3: Analysis Menu. Use of Variables in Program DTDHA. Program Description. References. Program Listing. 7. A Third Method of Evaluating the Well Equation. The Modified Sternberg Analysis, Program STRNBRG. Reference. Program Listing. 8. Two Dimensional (Matrix) Groundwater Model. Groundwater Matrix Models. Program ANMODL. Program Listing. 9. Plotting of Discharge Test Data. Computerised Plotting of Discharge Test Data. Plotter Commands. Program Listing. 10. Modelling Partial Aquifer Boundaries Using Image Wells. Hypothesis. Drawdown in a Two Part Aquifer, Program CONFDDB. Drawdown in a Semi-Strip Aquifer, Program CSTRIPB. Discharge from a Semi-Bounded Aquifer, Program SIM3B. Discharge from a Semi-Strip Aquifer, Program SIM5B. References. Program Listings. Appendices: Some differences in various implementations of BASIC. Practices adopted to improve speed and accuracy. Some comments on programming style and technique. Glossary. The relationships between the programs in this book. Index.