ABSTRACT
This chapter outlines the importance of groundwater, covering the key factors influencing the availability of the resource, including rainfall recharge and interactions with surface water bodies, and the key concept of water balance and how this is used in groundwater management. Groundwater aquifers are described and classified both conceptually and in terms of composition. The physical principles of groundwater flow are outlined, including the importance of Darcy’s Law, and the chapter describes how these principles inform groundwater maps and numerical flow simulations. Technologies for groundwater abstraction and reinjection are described and modern approaches to aquifer usage and management including use of groundwater for heating and cooling are outlined. Key aspects of groundwater chemistry and contamination are discussed. Natural groundwater chemistry is explained in terms of the origin of the groundwater and water–rock interactions such as mineral dissolution and weathering. Various geochemical types of groundwater are defined and their properties outlined. It is important to assess the vulnerability of groundwater to different types of human-induced contamination. The spatial and temporal characteristics of pollution sources and the subsurface behaviour of contaminant groups are therefore outlined.
