ABSTRACT
Hydrological processes are at the heart of the earth system. The hydrological cycle moves water from one store to another, and hydrological processes at the land surface strongly influence the partitioning of energy into latent and sensible heat. Water is an erosive agent, and acts as a solvent. It transports material from one place to another - it is the major source for many of the materials entering the ocean - and biogeochemical processes operating within water alter the speciation of elements. Ecosystems within a watercourse and along a floodplain are influenced by - and may be determined by - streamflow, soil moisture and groundwater regimes. People need water for drinking, washing, cooking and growing crops; industry uses water as a raw material and for cooling, power can be generated from running water, watercourses can be transport arteries, and rivers are also used to carry away waste.
