ABSTRACT
This chapter introduces the science of hydrology in relation to closely related disciplines and the work of the professional hydrologist. We discuss the importance of water and the physical and chemical properties of water that give rise to its unique characteristics in vapour, liquid and solid forms. We introduce the concept of a catchment (river basin), the global hydrological cycle and briefly consider the global distribution of freshwater resources. Components of the local hydrological cycle are introduced in the context of the water balance equation. We also introduce you to a fundamental concept underpinning much in hydrology; that of magnitude-frequency-duration relationships.
