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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]
A discharge is a measure of the quantity of any fluid flow over unit time. The quantity may be either volume or mass. 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.
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.
Measure a length of stream, and mark the start and finish points. The longest length without changing stream conditions is desired to obtain the most accurate measurement. Place an orange at the starting point and measure the time for it to reach the finish point with a stopwatch. Repeat this at least three times and average the measurement times.
Georeferenced map images are available from the USGS as digital raster graphics (DRGs) in addition to digital data sets based on USGS maps, notably digital line graphs (DLGs) and digital elevation models (DEMs). In 2015, the USGS unveiled the topoView website, a new way to view their entire digitized collection of over 178,000 maps from 1884 to ...
The USGS also measured discharge at the village of Larrys Creek, very near the creek's mouth, as part of water quality measurements on seven occasions between 1970 and 1975. The average discharge was 66.0 cubic feet per second (1.87 m 3 /s), and ranged from a high of 114 cubic feet per second (3.23 m 3 /s) to a low of 8.8 cubic feet per second ...
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. For context, the volume of an Olympic-size swimming pool is 2,500 m 3 (88,000 cu ft). The average flow rate at the mouth of the Amazon is sufficient to fill ...
The short-section Parshall (sometimes referred to as a USGS or Portable Parshall) omits the discharge section of the flume. Originally designed by Troxell and Taylor in 1931 and published under "Venturi Flume" as a memorandum from the office of the Ground Water Branch, USGS, the design was again brought to the attention of potential users in ...