Hydrology is primarily concerned with the amounts and quality of water moving and accumulating on the land surface and in the soils and rocks near the surface. It therefore encompasses water in rivers, lakes, aquifers and glaciers.
Hydrology embraces a wide range of interests including scientific and engineering applications.
Hydro-meteorology spans the interface between meteorology and hydrology, and professionals active in this subject may have trained in either or both disciplines. Hydro-geology addresses the science of water in the ground and has, as its name suggests, a close affinity with the geological sciences. Hydrologists undertake a wide range of activities in order to monitor, manage and protect the water environment. Many activities and studies would be impossible without hydrometric data measurement, collection and archiving. Hydrologists frequently develop and use mathematical models to mimic the physical processes.