where do rivers start? Can we trace rivers to a spot where it starts to pour out like a tap?
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Yes. You can trace every river to a starting point. Whether it’s coming from a lake, a spring, another river, an underground water table, whatever. Every river has a starting point.
Most rivers start in the mountains, flow towards lower ground because of gravity, and eventually into a lake or the ocean.
The water rarely comes from a single source, especially if it’s a big river (system). Usually they come from a whole area and is the result of rain pour and melting snow/ice in the mountains.
Trickles of water from melting snow flow together. These flow together with other trickles until there is enough water for a stream. Streams flow together until there is enough water to call it a river.
You have probably heard about something called the “water cycle”. Water evaporates into the air, forms into clouds, and rains back down onto the land as fresh water. That water obeys gravity and runs downhill. A “drainage basin” is an area where “downhill” all eventually comes together, so water falling into the drainage basin will eventually collect together into small streams, then large streams, and eventually rivers.
Where exactly the line is drawn between those things is somewhat arbitrary. Enough streams come together and become large enough and it becomes a river, and that is where the rivers “start”. A river might also end when it drains into another, larger or more important river. Eventually that water almost always makes its way to the ocean.
Is pretty crazy to see where the Mississippi starts in Minnesota and then where it ends. It’s quite the growth the river experiences over the 1500 miles or whatever
Rivers start when tributaries come together. Sometimes when two rivers come together and form a really big river, the big river gets a new name.
As others have said, you trace back the river and you’ll find it splits into smaller streams.
When we talk about the source of a river, we generally consider it to be the source furthest from the mouth of the river.
Top Gear (of all people) did a surprisingly good episode where they tried to find the “true” source of the Nile.
The biggest difficulty with “where a river starts” isn’t finding where the water starts, but deciding which specific creek that wouldn’t wet your ankles that feeds into what becomes the river counts as “the” river.
See the debates about the sources of the Nile and Amazon.
That said, yes, you can go to the specific hill where any stream starts. Although sometimes it’s difficult to tell. Some rivers start as springs pouring out of the ground or meltwater flowing from under a glacier or a creek flowing out of a lake, those are easy.
But other rivers, that are fed by rainwater straight from a hill, start as… Rainwater. Flowing on the ground. So you go to a hill that “the source” and you either see just some rain runoff, or nothing if it’s not raining, because the soil’s just draining downhill. The stream just sort of gradually appears, without a clear indication when you’re really free to call it a stream and not just “runoff”.
Source: I’ve been to a places like that, all variations.
I thought this was a dumb question, not fitting this sub, but reading the replies, I see it might not be.
Water that will become rivers (or streams, brooks, creeks, there’s no official definition of river, it’s all just colloquial names) usually comes from either a spring or a glacial lake.
A spring is a point where underground water from an aquifer emerges to the surface. There is often literally a human constructed tap you can drink out of.
Aquifer is water underground, but it’s not like a lake of water in a cave, the water is in the ground itself, similar to when you pour water on the ground and it disappears. At some places, there is are ground layers that will let water through followed by a ground layer that will not let water through anymore (bedrock) and that’s where aquifers form. This is also how wells work, btw.
Glacial lakes are usually formed in a basin in a mountain, and they aren’t fed by another river, but rather by rain and snow melting and flowing into the lake. Rivers can flow out of them.
Most rivers will eventually flow into another body of water (and I mean really almost all of them). Often it’s another river, and then the smaller rivers are called the bigger river’s tributaries. Some rivers “originate” at a spot where two or more tributaries meet, but that just means they are named a new name at that spot. Most rivers are tracked through a single stem to some source I described above. This is called a main stem. But there’s usually not really a “real” way to differentiate between which river is the tributary and which is the main river. It’s usually just done based on which river is bigger or based on the angle.
Many comments here seem to misunderstand what “drainage basin” means. Drainage Basin is an area from which all flowing water eventually converges to a single spot. It can be defined for any body of water, and drainage basins will include other drainage basins. It is not related to rain and snow flowing into some basin and forming rivers.
For example, let’s say river A flows into river B, rivers C and D flow into river E, which then flows into river B, which the flows into some sea. The drainage basin of river E containes the are around rivers C and D. The drainage basin of river B containes the area around river A and the entire drainage area of river E. The drainage area of that sea containes the drainage area of river B (plus sny other rivers that flow into it).
If you search for maps of a “watershed” you will see that a river is something like a “reverse” tree branch. Water rolls downhill from melting snow in very small quantities, and then because of gravity just pools together on its way down and eventually comes a noticeable moving body of falling/rolling water. While you can designate one spot as the “beginning” of a river, it will be a small outflow from a mud puddle from melting snow on a hillside, that single spot isn’t really the source of the river. It’s just one of many sources of the start of a river. You might look at the topography of a flowing body of water and determine that some of the water continues on the same trajectory, while others flow into that trajectory.
So going upstream, we have one outflow to the ocean, one river, two or three tributaries, a dozen branches, dozens of streams, hundreds of little creeks flowing into those, and thousands of little runoffs in the mountains.
The river isn’t going from point A to point B itself as much as the river is “draining” the water out of a certain area of land.
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