hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

, stage is the

water level Water level, also known as gauge height or stage, is the elevation of the free surface of a sea, stream, lake or reservoir relative to a specified vertical datum. Over long distances, neglecting external forcings (such as wind), water level ten ...

in a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

with respect to a chosen

reference height In geodesy, surveying, hydrography and navigation, vertical datum or altimetric datum is a reference coordinate surface used for vertical positions, such as the elevations of Earth-bound features (terrain, bathymetry, water level, and built struc ...

. It is commonly measured in units of feet. Stage is important because direct measurements of

river discharge In hydrology, discharge is the volumetric flow rate (volume per time, in units of m3/h or ft3/h) of a stream. It equals the product of average flow velocity (with dimension of length per time, in m/h or ft/h) and the cross-sectional area (in m2 o ...

are very difficult while water surface elevation measurements are comparatively easy. In order to convert stage into discharge, a ''

rating curve In hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is ...

'' is needed. Hydrologists can use a combination of tracer studies, observations of

high water mark A high water mark is a point that represents the maximum rise of a body of water over land. Such a mark is often the result of a flood, but high water marks may reflect an all-time high, an annual high (highest level to which water rose tha ...

s, numerical modeling, and/or

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

aerial photography Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other flight, airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wi ...

References

Hydrology Vertical position {{geo-term-stub

See also

References