Contents
1 Introduction 1
Scope. Historical Background. Utilization of Ground Water. Ground Water in the Hydrologic Cycle. Literature and Data Sources.
2 Occurrence of Ground Water 14
Origin of Ground Water. Rock Properties Affecting Ground Water, Vertical Distribution of Ground Water. Geologic Formations as Aquifers. Types of Aquifers. Ground Water Basins. Springs. Ground Water in Permafrost Regions. Ground Water in the United States.
3 Ground Water Movement 44
Darcy's Law. Coefficient of Permeability. Ground Water Flow Rates. Permeability Formulas. Laboratory Measurement of Permeability. Field Measurement of Permeability. Tracing Ground Water Movement. General Flow Equations. Ground Water Flow Lines. Unsaturated Flow.
4 Ground Water and Weil Hydraulics 78
Steady Unidirectional Flow. Steady Radial Flow to a Well. Well in a Uniform Flow. Steady Flow with Uniform Recharge. Unsteady Radial Flow to a Well. Nonequilibrium Equation for Pumping Tests. Well Flow Near Aquifer Boundaries. Multiple Well Systems. Partially Penetrating Wells. Characteristic Well Losses.
5 Water Wells 115
Test Holes and Well Logs. Methods for Constructing Shallow Wells. Methods for Drilling Deep Wells. Well Completion. Well Development. Testing Wells for Yield. Pumping Equipment. Sanitary Protection of Wells. Maintenance and Repair of Wells. Collector Wells. Infiltration Galleries.
6 Ground Water Levels and Fluctuations 149
Secular and Seasonal Variations. Streamflow and Ground Water Levels. Fluctuations Due to Evapo transpiration. Fluctuations Due to Meteorological Phenomena. Fluctuations Due to Tides, External Loads, and Earthquakes. Control by Drains and Wells.
7 Quality of Ground Water 177
Sources of Salinity. Ground Water Samples. Measures of Water Quality. Chemical Analysis. Physical Analysis. Bacterial Analysis. Water Quality Criteria. Base Exchange. Deterioration of Ground Water Quality. Temperature.
8 Basin-Wide Ground Water Development ..... 200
Safe Yield and Overdraft. Factors Governing Safe Yield. Equation of Hydrologic Equilibrium. Data Collection for Basin Investigations. Methods of Computing Safe Yield. Variability of Safe Yield. Conjunctive Use of Surface and Ground Water Reservoirs.
9 Surface Investigations of Ground Water 219
Geophysical Exploration. Electrical Resistivity Method. Seismic Refraction Method. Gravity and Magnetic Methods. Geologic Methods. Air Photo Interpretation. Dowsing.
10 Subsurface Investigations of Ground Water .... 235
Test Drilling. Resistivity Logging. Potential Logging. Temperature Logging. Caliper Logging. Other Subsurface Methods.
11 Artificial Recharge of Ground Water ..... 251
Artificial Recharge in the United States. Water Spreading. Research on Water Spreading. Sewage Recharge. Recharge through Pits and Shafts. Recharge through Wells. The Manhattan Beach Recharge Project. Recharge Wells on Long Island, New York. Recharge Wells for Storm Drainage. Induced Recharge. European Recharge Practices.
12 Sea Water Intrusion in Coastal Aquifers 277
Occurrence of Sea Water Intrusion. Ghyben-Herzberg Relation between Fresh and Saline Waters. Shape of the Fresh-Salt Water Interface. Length of the Intruded Sea Water Wedge. Structure of the Fresh-Salt Water Interface. Prevention and Control of Sea Water Intrusion. Field Tests for Controlling Intrusion at Manhattan Beach, California. Fresh-Salt Water Relations on Oceanic Islands. Recognition of Sea Water in Ground Water.
13 Legal Aspects of Ground Water 297
Systems of Title to Ground Water. Legal Interpretation of Ground Water. Ground Water Law in the United States. Water Rights in Overdraft Areas. Statutory Control of Recharged Ground Water. Common Regulations Applying to Ground Water.
14 Model Studies and Numerical Analysis of Ground Water . 307
Sand Models, Electrical Models. Viscous Fluid Models Membrane Models. Numerical Analysis Methods.
Appendix 327
Conversion Factors and Constants.
Index 329
*
Preface
Water is an essential commodity to mankind, and the largest available source of fresh water lies underground. Increased demands for water have stimulated development of underground water supplies. Inevitably, when progress magnifies and adds new problems, efforts are increased to solve these problems. This is especially true for ground water. Methods for investigating the occurrence and movement of ground water have been improved, better means for extracting ground water have been developed, principles of conservation have beto established, and research of several types has contributed to a better understanding of the subject. As a result, knowledge of ground water hydrology, once veiled in mystery, has expanded rapidly in recent decades. Anticipating the ever-increasing use of ground water, it is reasonable to presume that such knowledge will grow at an even greater rate in the future.
My purpose in writing this book has been to present the fundamentals of ground water hydrology in a manner understandable to those most concerned with such knowledge. Few men specialize in ground water hydrology, yet, because ground water is a major natural resource, it is important to students and professional men in a variety of fields. Chief among these are civil engineers (including specialists in hydraulics, hydrology, sanitary engineering, soil mechanics, and water resources), geologists, and agricultural and irrigation engineers. Personnel in charge of municipal and industrial water supplies often have a vital interest in ground water. Men indirectly concerned can be found in the fields of mining, petroleum engineering, forestry, public health, and law, among others. Although it is impossible to present a subject fitted to the requirements of such a diversity of interests, the common need of all is an understanding of the fundamental principles, methods, and problems encountered in the field as a whole. Thus, this book is an effort to make available a unified presentation of ground water hydrology.
This book presupposes only a background of mathematics through calculus and an elementary knowledge of geology. I believe previous instruction in fluid mechanics and hydrology to be desirable but not essential.
By emphasizing only fundamental considerations of ground water, I have tried to restrict the book to a practical size without impairing its scope. A consistent nomenclature has been adopted with clarity as the criterion, although equivalent well-established expressions are mentioned to avoid confusion. Illustrative examples from field data have been minimized, mainly because of their ready availability elsewhere. Publications of the United States Geological Survey are extensive and contain a wealth of material collected from field investigations. Also, many state water resource agencies have published comprehensive reports of local ground water situations. For instructors using this book as a text, I recommend that data from these sources be presented in the form of illustrations and problems to supplement the text material.
The contents of the book are based on a broad interpretation of ground water hydrology in order to embrace all elements of ground water as a water supply source. The first six chapters cover the basic quantitative aspects of the subject, including use, occurrence, movement, hydraulics, water wells, and ground water levels. Chapter 7 presents ground water quality, a topic as important as ground water quantity, with emphasis on measures of water quality and interpretation of water analyses. Chapter 8 is concerned with the conservation of ground water, expressed by safe yield, and maximum water development by conjunctive use with surface water. Methods for investigating ground water by surface and subsurface procedures are described in Chapters 9 and 10. Two important problems unique to ground water hydrology are artificial recharge and sea water intrusion; these are discussed in Chapters 11 and 12. Economic and legal considerations affect ground water development. Economic aspects are included in Chapter 8, and Chapter 13 provides an introduction to ground water rights, a subject of considerable interest in the last decade in the United States. The final chapter contains a review of the various types of laboratory model and numerical analysis studies that have become valuable ground water research tools. An appendix lists useful conversion factors and constants.
At the end of each chapter appears a list of references pertaining to the specific topic treated. The ground water literature is voluminous, and a comprehensive bibliography not only would be a major undertaking but also would serve little practical purpose except for research workers. Therefore, I have tried to select those references which ould be most helpful to the reader desiring more information on a given topic. For many readers the references listed will be sufficient; for others wishing to go further, they will serve only as a beginning. Included in the references at the end of the first chapter are general references and a few foreign books.
Many persons have assisted me, directly and indirectly, in the preparation of this book, including my colleagues at the University of California, members of the California Department of Water Resources, and members of the United States Geological Survey. In Europe, help on special topics was generously given by several engineers and geologists. Questions and reaction of students guided me in the presentation of many topics. Specific chapters were reviewed by F. B. Clendenen, S. T. Harding, and J. F. Poland. To all of these, and to my wife, I should like to acknowledge my indebtedness.
David Keith Todd
Berkeley, California March 1959
