Page 18 - Hydrogeology Principles and Practice

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1

Introduction

1.1 Scope of this book theme of this book. By studying topics such as the
properties of porous material, groundwater flow the-
This book is about the study of hydrogeology and the ory, well hydraulics, groundwater chemistry, envir-
significance of groundwater in the terrestrial aquatic onmental isotopes, contaminant hydrogeology and
environment. Water is a precious natural resource, techniques of groundwater remediation and aquifer
without which there would be no life on Earth. We, management, it is the responsibility of us all to man-
ourselves, are composed of two-thirds water by body age groundwater resources to balance environmen-
weight. Our everyday lives depend on the availability tal, economic and social requirements and achieve
of inexpensive, clean water and safe ways to dispose sustainable groundwater development (Fig. 1.1).
of it after use. Water supplies are also essential in sup- The eight main chapters of this book aim to pro-
porting food production and industrial activity. As a vide an introduction to the principles and practice of
source of water, groundwater obtained from beneath hydrogeology and to explain the role of groundwater
the Earth’s surface is often cheaper, more convenient in the aquatic environment. Chapter 1 provides a
and less vulnerable to pollution than surface water. definition of hydrogeology and charts the history
Groundwater, because it is unnoticed underground, of the development of hydrogeology as a science.
is often unacknowledged and undervalued resulting The water cycle is described and the importance of
in adverse environmental, economic and social con- groundwater as a natural resource is explained. The
sequences. The over-exploitation of groundwater by legislative framework for the protection of ground-
uncontrolled pumping can cause detrimental effects water resources is introduced with reference to
on neighbouring boreholes and wells, land subsid- industrialized and developing countries. Chapters 2
ence, saline water intrusion and the drying out of and 3 discuss the principles of physical and chemical
surface waters and wetlands. Without proper con- hydrogeology that are fundamental to an under-
sideration for groundwater resources, groundwater standing of the occurrence, movement and chemistry
pollution from uncontrolled uses of chemicals and of groundwater in the Earth’s crust. The relationships
the careless disposal of wastes on land cause serious between geology and aquifer conditions are demon-
impacts requiring difficult and expensive remediation strated both in terms of flow through porous material
over long periods of time. Major sources of contam- and rock–water interactions. Chapter 4 provides an
ination include agrochemicals, industrial and muni- introduction to the application of environmental iso-
cipal wastes, tailings and process wastewater from topes in hydrogeological investigations for assessing
mines, oil field brine pits, leaking underground stor- the age of groundwater recharge and includes a sec-
age tanks and pipelines, and sewage sludge and septic tion on noble gases to illustrate the identification of
systems. palaeowaters and aquifer evolution.
Achieving sustainable development of ground- In the second half of this book, Chapter 5 provides
water resources by the future avoidance of over- an introduction to the range of field investigation
exploitation and contamination is an underlying techniques used in the assessment of catchment water