The Groundwater Project

Basic Hydrogeology

An Introduction to the Fundamentals of Groundwater Science

Matthew Ulliana Book Cover
Publication year: 2025
Number of pages: 283

978‑1‑77470‑065‑5
https://doi.org/10.62592/CBIQ7579

Citation:

Uliana, M. M. (2025). Basic hydrogeology: An introduction to the fundamentals of groundwater science. The Groundwater Project. https://doi.org/10.62592/CBIQ7579.

Author:

Matthew M. Uliana: INTERA Geosciences, Australia

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Last Update: 19 January 2025
Released: 13 January 2025

Description

A number of excellent textbooks on hydrogeology are available to students and practitioners of the science, including several classic manuscripts available for free download through this website. Comprehensive textbooks such as these, however, may not be best for guiding an introductory level course for undergraduate students who intend to work in the industry. Like other sciences, hydrogeology is an extensive and complex field of study that is governed by a much smaller number of underlying concepts; e.g., flow is driven by a hydraulic head gradient, properties of subsurface formations control groundwater velocities and volumetric flow rates in response to a gradient, pumping water wells represent a specific type of flow system, etc.

Students preparing for work in hydrogeology consulting or regulatory compliance need to be educated with a focus on those concepts and on applying those concepts to the types of problems that working hydrogeologists face on a regular basis. This book is not intended to replace or substitute for the many existing textbooks on groundwater hydrology. Rather, the intent is to provide an educational resource that can be directly used by hydrogeology teachers to support an undergraduate course in groundwater hydrology. The fundamentals of the science, including hydraulic head and head gradients, the properties of porous media, the equations governing flow in groundwater systems, flow to pumping water wells, and groundwater modeling are included, along with other related topics (e.g., geochemistry, the unsaturated zone, consolidation and subsidence, and surface water hydrology). A number of exercises are included, along with solutions.

Interview with the Author

Contents

1 INTRODUCTION TO HYDROGEOLOGY

1.1 The Properties Of Water

1.2 Distribution Of Water On The Earth

1.3 The Hydrologic Cycle

1.3.1 Systems
1.3.2 Cycles
1.3.3 Overview of the Hydrologic Cycle

1.4 Groundwater

1.4.1 Distribution of Water in the Subsurface
1.4.2 Recharge and Discharge
1.4.3 Groundwater Flow
1.4.4 Aquifers

2 POTENTIAL AND KINETIC ENERGY IN SUBSURFACE FLUIDS

2.1 Introduction

2.2 Fluid Energy

2.2.1 What do we mean by Energy?
2.2.2 The Bernoulli Equation
2.2.3 Hydraulic Head and Hydraulic Potential
2.2.4 Physical Description of the Components of Head
2.2.5 Distribution of Head (i.e., fluid energy) in a 3 D Aquifer
2.2.6 Why Do We Care About This?

3 POROUS MEDIA

3.1 Introduction

3.2 Porosity

3.2.1 Density
3.2.2 Moisture Content
3.2.3 Geologic Materials and Implications for Fluid Flow

3.3 Permeability

3.3.1 Darcy’s Law
3.3.2 What Does This Mean?
3.3.3 Permeability for Other Fluids
3.3.4 Other Famous Equations Analogous to Darcy’s Law
3.3.5 The Limits of Darcy’s Law
3.3.6 Measuring Permeability
3.3.7 Fluid Velocity
3.3.8 Permeability Distributions in Aquifers
3.3.9 Statistical Distribution

4 FLOW EQUATIONS

4.1 Introduction

4.2 Equations: A General Discussion

4.3 Darcy’s Law

4.4 Groundwater Flow Equations

4.4.1 Differential Equations
4.4.2 What Does This Mean in Conceptual Terms?
4.4.3 How Do We Solve These Equations?

5 STORAGE PARAMETERS AND AQUIFER CONDITIONS

5.1 Introduction

5.2 Aquifers

5.3 Storage Parameters

5.3.1 Confined Aquifers—A Conceptual Understanding
5.3.2 Confined Aquifers—A Mathematical Understanding
5.3.3 Unconfined Aquifers

6 MORE ON FLOW EQUATIONS

6.1 Introduction

6.2 Steady State Versus Transient Groundwater Flow

6.2.1 Steady State Flow
6.2.2 Transient Flow

6.3 Flow Calculations and Applications of the Flow Equation

6.3.1 Steady State Flow in a Confined Aquifer
6.3.2 Steady State Flow in an Unconfined Aquifer
6.3.3 Flow Lines and Flow Nets

7 WELL HYDRAULICS

7.1 Introduction

7.2 Background Information on Wells

7.2.1 Basic Well Construction
7.2.2 Well Development

7.3 Well Hydraulics

7.3.1 Horizontal Radial Flow

7.4 The Theis Equation

8 AQUIFER TESTING

8.1 Introduction

8.2 Well Hydraulics—A Quick Review

8.3 Aquifer Tests and Ideal Drawdown Curves

8.3.1 Multi Well Aquifer Test
8.3.2 Drawdown Curves

8.4 Aquifer Test Analysis

8.4.1 The Theis Curve Matching Method for Non Leaky (i.e., fully confined) Aquifers
8.4.2 Leaky Confined and Unconfined Methods

8.5 Simplification Of The Theis Equation

8.5.1 Time Drawdown Method
8.5.2 Distance Drawdown Method

8.6 Single Well Aquifer Tests

8.6.1 Limitations of Single Well Tests

8.7 Well Loss and Well Efficiency

8.7.1 Drawdown and Fluid Energy
8.7.2 Specific Capacity and Step Rate Tests
8.7.3 Example step rate test with analysis

8.8 Slug Tests

8.8.1 Test Procedure
8.8.2 Potential Problems with Slug Tests

8.9 Multiple Wells, Boundaries, And Image Wells

8.9.1 Superposition 96
8.9.2 Use of Image Wells to Represent Boundaries

9 GROUNDWATER FLOW SYSTEMS

9.1 Review of Sections 1 to 8

9.2 Characteristics of Flow Systems

9.2.1 Boundary Conditions
9.2.2 Recharge
9.2.3 Discharge
9.2.4 Heterogeneity and Anisotropy
9.2.5 Relationship between Topography and Flow Systems

10 FLOW MODELING

10.1 Introduction

10.2 Models: A General Definition and Specific Details

10.2.1 Why Do We Use Process Models?

10.3 Specific Types of Groundwater Flow Models

10.3.1 Qualitative Models
10.3.2 Conceptual Hydrogeological Models
10.3.3 Physical or Analog Models
10.3.4 Mathematical Models

10.4 The Method of Finite Differences

10.5 An Introduction to Modflow

11 GROUNDWATER CHEMISTRY

11.1 Introduction

11.2 First, a Little Background Chemistry

11.2.1 Basic Chemistry Concepts and Definitions
11.2.2 Atomic Mass and the Mole
11.2.3 Concentrations of Solutions

11.3 Water Analysis and Naturally Occurring Dissolved Species

11.3.1 Basic Chemical Parameters

11.4 A Little About Chemical Reactions

11.5 Inferences About Groundwater Flow Systems

11.6 Graphical Representations of Geochemical Data

11.6.1 Piper Diagrams
11.6.2 Stiff Diagrams
11.6.3 Case study: Using Geochemical Diagrams to Identify a Contamination Source
11.6.4 Schoeller Diagrams

11.7 Evaluation of Water Quality Data

11.8 Additional References

12 MASS TRANSPORT

12.1 Introduction

12.2 Mass Transport in Groundwater

12.2.1 Advection
12.2.2 Dispersion

12.3 Reactions and Retardation

12.4 Mass Transport Equations

12.5 Management of Groundwater Contamination

12.5.1 Capture Zone Analysis

13 SURFACE WATER

13.1 Introduction

13.2 Basics of Surface Water

13.3 Evaporation, Transpiration, and Precipitation

13.3.1 Evaporation
13.3.2 Transpiration
13.3.3 Evapotranspiration
13.3.4 Precipitation

13.4 What Happens When it Rains?

13.5 Streams

13.5.1 Discharge
13.5.2 Manning Equation
13.5.3 Stream Hydrographs

14 UNSATURATED ZONE

14.1 Introduction

14.2 Distribution of Water in the Shallow Subsurface

14.2.1 Saturation
14.2.2 Capillary Forces

14.3 Movement of Water in the Vadose Zone

14.3.1 Moisture Content
14.3.2 Pore–Water Tension

14.4 Theory of Flow in an Unsaturated Porous Medium

14.5 Studying the Unsaturated Zone: Instruments and Techniques

15 CONSOLIDATION AND SUBSIDENCE

15.1 Introduction

15.2 Review of Elastic Response in A Confined Aquifer

15.3 States of Stress in the Earth’S Crust

15.4 Compressibility and Storage Parameters

15.5 Land Subsidence

16 FLOW IN NON POROUS MEDIA

16.1 Introduction

16.2 Conceptualizing Fractured Media

16.3 Fracture Properties

16.3.1 Orientation
16.3.2 Aperture
16.3.3 Length, Width, and Depth
16.3.4 Spacing and Density
16.3.5 Connectivity

16.4 Formation of Fractures

16.5 Hydraulic Properties of Fractures

16.5.1 Porosity
16.5.2 Permeability

16.6 Modeling Fluid Flow in Fractures

16.6.1 Parallel Plate Model
16.6.2 Discrete Fracture Model
16.6.3 Stochastic Models
16.6.4 Double Porosity Models
16.6.5 Equivalent Porous Media
16.6.6 Equivalent Porous Media with Fracture Domains

16.7 Influence of Fractures on Fluid Flow and Mass Transport

17 GROUNDWATER IN VARIOUS GEOLOGIC SETTINGS

17.1 Introduction

17.2 Basic Classification of Hydrogeologic Environments

17.3 Alluvium

17.3.1 Alluvial Fans
17.3.2 Deltas
17.3.3 Floodplain/river Valley Deposits

17.4 Glacial Deposits

17.5 Clastic Sedimentary Rocks—Sandstone/Shale

17.6 Chemical Sedimentary Rocks—Carbonates and Evaporites

17.7 “Hard” Rocks

18 WRAP-UP

18.1 PART 1: Fundamentals

18.2 Part 2: Related Topics

19 EXERCISES

20 REFERENCES

21 BOXES

Box 1 – Derivation of the Radial Flow Equation

22 EXERCISE SOLUTIONS

23 THOUGHT QUESTIONS ANSWERED

24 NOTATIONS

25 ABOUT THE AUTHOR