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Thus the water discharge of a tap (faucet) can be measured with a measuring jug and a stopwatch. Here the discharge might be 1 litre per 15 seconds, equivalent to 67 ml/second or 4 litres/minute. This is an average measure. For measuring the discharge of a river we need a different method and the most common is the 'area-velocity' method.
The first routine measurements of river flow in England began on the Thames and Lea in the 1880s, [2] and in Scotland on the River Garry in 1913. [3] The national gauging station network was established in its current form by the early 1970s and consists of approximately 1500 flow measurement stations supplemented by a variable number of temporary monitoring sites. [2]
Here, only those rivers whose discharge is more than 2,000 m 3 /s (71,000 cu ft/s) are shown. It can be thought of as a list of the biggest rivers on Earth, measured by a specific metric. It can be thought of as a list of the biggest rivers on Earth, measured by a specific metric.
All rivers with average discharge more than 15,000 cubic feet per second are listed. Estimates are approximate, because data are variable with time period measured and also because many rivers lack a gauging station near their point of outflow.
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.
In hydrology, a rating curve is a graph of discharge versus stage for a given point on a stream, usually at gauging stations, where the stream discharge is measured across the stream channel with a flow meter. [1] Numerous measurements of stream discharge are made over a range of stream stages.
In very deep water they can be lowered on cables from the surface. The primary usage is for oceanography. [4] The instruments can also be used in rivers and canals to continuously measure the discharge. Mounted on moorings within the water column or directly at the seabed, water current and wave studies may be performed. They can stay ...
The discharge is measured at a specific point in a river and is typically time variant. Approach Segment the river flow before the storm (antecedent flow). Rising limb The rising limb of the hydrograph, also known as concentration curve, reflects a prolonged increase in discharge from a catchment area, typically in response to a rainfall event.