A practitioner of hydrology, or hydrologist, may work in any of several fields: earth science, environmental science, physical geography, civil engineering, and environmental engineering.
The central theme of hydrology is that water moves throughout the Earth by different pathways and at different rates.
The nineteenth century saw development in groundwater hydrology, including Darcy's law, the Dupuit-Thiem well formula, and Hagen-Poiseuille's capillary flow equation.
Pioneers of the modern science of hydrology include Pierre Perrault, Edme Mariotte, and Edmund Halley.
Hydrolysis is a chemical weathering process affecting silicate minerals (compounds containing silicon, oxygen, and a metal).