There must be a formula because otherwise, how could you specify how long it was?
2007-02-14 23:38:05 · 7 answers · asked by mikethutchinson 1 in Science & Mathematics ➔ Geography
It's from where the largest amount of water is coming out of the ground which starts the stream
2007-02-14 23:51:13 · answer #1 · answered by Norton G 6 · 0⤊ 0⤋
The official Ordnance Survey method is to follow the river upstream. At each confluence, (junction), you take the stream with the largest flow, etc etc etc.
It won't necessarily mean you find the path with the longest length.
For instance, the River Thames has an official source at Thames Head near Kemble, Glos. The longest path starts from Seven Springs near Cheltenham, Glos.
2007-02-15 11:26:25 · answer #2 · answered by efes_haze 5 · 0⤊ 0⤋
River surveyors follow the river upstream. Every place where it merges with another stream, they determine which is the biggest. The smaller stream is considered a tributary, and the bigger stream is the main river. They keep going until they get to a lake, or a spring.
If it's a lake, they have to find the biggest stream feeding the lake, and follow that upstream.
2007-02-15 10:16:36 · answer #3 · answered by morningfoxnorth 6 · 0⤊ 0⤋
The source of the river is considered to be the point where the longest tributary rises.
2007-02-15 07:47:59 · answer #4 · answered by Gnomon 6 · 0⤊ 0⤋
any water that flows into a river is a source. I would imagine that you can have a permanent source, and that would a source you can count on, and that is how they would specify how long it is
2007-02-15 07:51:19 · answer #5 · answered by Reglone1998 2 · 0⤊ 0⤋
Inquiring minds follow and make measurements.
2007-02-15 07:45:34 · answer #6 · answered by redunicorn 7 · 0⤊ 0⤋
People have to go and look.
2007-02-15 07:41:01 · answer #7 · answered by cuddles_gb 6 · 0⤊ 0⤋