Streamflow, or channel runoff, is the flow of water in streams, rivers, and other channels, and is a major element of the water cycle. It is one component of the runoff of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel. A girl in a swimming pool full of water Water (from the Old English waeter; c. ... A running stream. ... The Murray River in Australia. ... In physical geography, a channel is the physical confine of a river or slough, consisting of a bed and banks. ... The movement of water around, over, and through the Earth is called the water cycle. ... Runoff is the flow of water across the earths surface, and is a major component in the hydrological cycle. ... Runoff flowing into a stormwater drain Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle[1][2]. Runoff that occurs on surfaces before reaching a channel is also called overland flow. ... Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations. ... In hydrology, the discharge of a river is the volume of water transported by it in a certain amount of time. ... A stream gage refers to a site along a stream where measurements of volumetric discharge (flow) are made. ... The Manning formula is an empirical formula for open channel flow, or flow driven by gravity. ... There are two meanings for hydrographs both coming from hydro- meaning water, and -graph meaning chart; a record through time of discharge (flow) in a stream, or a record through time of water level in an aquifer, measured in a well. ... Look up Flood in Wiktionary, the free dictionary. ...

See also

• Drainage basin or watershed
• Drainage network
• Water resources

For the term related to television programmes, see watershed (television). ... Water resources are sources of water that are useful or potentially useful to humans. ...

Reference

• USGS Water Science Basics