WHERE AND HOW ARE RIVERS BORN? - ENVIRONMENT - 2025

The rivers are streams or freshwater streams that rise in the mountains and hills, and travel to the lower parts of the earth, the land relief being the determining factor of its main features. It is there, in the highlands, where its birth occurs, also called its source of origin or head.

They flow through mouths or outlets, into lakes or seas, through channels called drains that were generated over many years. In turn, through these channels, which can be of different sizes and depths, the waters flow downwards, in search of their mouth.

Rivers contain fresh water and in it, an aquatic world full of life. Their flow increases or decreases depending on various factors, such as climatic and geological changes, or those produced by man himself.

Through the different geographical spaces present on earth, the river takes its course, always in constant motion, to find its mouth.

How is the source of a river produced?

The place where a river is formed or born corresponds to its source or its head. It is from there from where the water currents are formed, which travel along long paths, to their mouth.

However, the source of a river can occur in various ways. One of them refers to the water that gushes from the earth, which was deposited below it. Product generally of the fluvial precipitations.

This accumulation of this underground fluid is previously produced by rain. In other words, when it rains, a quantity of water is filtered or deposited below the earth, which, when grouped or accumulated, naturally emerges towards the surface.

Now, before this happens, this liquid from under the Earth has previously traveled for several kilometers in which various sediments and rocks are present that intervene as natural filters, removing any type of contaminant existing in it from the water, and in addition, providing it with various minerals.

That is why rivers are considered natural sources of water of excellent quality and rich in minerals, where mineral water is usually extracted for its preparation.

Another form referring to the source of rivers, refers to the fall of rainwater in the upper parts of the earth, such as mountains or hills. This water is not absorbed by the earth, running along the surface of it, towards lower parts.

Also the rivers can have their origin from the melting of the glaciers, following the flow or current of the water the course from a higher part or peak to a lower one.

These waters, which come together making the riverbed grow, are the ones that later form streams or streams.

What is the course of a river?

The course of a river refers to the route that it takes, from its source, to its mouth either in another river, or in the sea.

The course of a river is also called a fluvial course, presenting various characteristics, among them, varied lengths, more or less inclined slopes, greater or lesser amounts of water, among others.

In the mountain where the river finds its origin, there are different formations known as basins, through which the river begins to form when the water passes through them.

The basins present at the top of the hills and mountains are characterized by being narrow and steep. They are usually surrounded by valleys and geological formations that produce the changes of direction to which the river adapts as it finds its way through them.

The steeper there is, that is, the closer to the head of the river we are, it will be possible to visualize that the water will flow more quickly, thus being how waterfalls are generated.

At the same time, in its rapid flow, the water is generating the wear of the natural materials that it finds in its path, causing its erosion. From each basin, the river begins to slide forming what is called a stream.

When these diverse basins are combined, the streams originate, which unite to form larger flows and flows of water, finally merging into a river and giving rise to the river's hydrographic basin.

These channels and streams are what are called the tributaries of the rivers. Now, rivers can flow into a lake, or into the sea, but they can also flow into another river, these being the tributary rivers.

What are the characteristics of the course of a river?

The course or route of a river is characterized by presenting three sections. From the headland down a high course, a medium course and a low course can be located.

High course

The upper course of a river includes its head, that is, where it originates and the first kilometers of its route. It is the place where large slopes predominate, which cause the river to flow with high energy and at high speed.

In the upper course of the river, its channel is narrow and has little depth. This is where the waters that emerged to the surface that gave rise to the formation of the river flow and pass.

The speed and force with which the river moves in this section, produced by the great slopes present at the headwaters, cause the water to form channels or deep gorges giving rise to waterfalls.

Middle course

The middle course of a river refers to the area where it flows more smoothly, because the slopes present a lower degree of inclination with respect to the upper course.

At the same time, in its middle course, the river increases its channel as it converges with its tributaries, eroding the land and depositing its sediments, along its route to its mouth.

It is in the middle course of the river where small curves or undulations can occur, which are called meanders, due to the decrease in the speed at which the water flows and the change of course that it undergoes.

Low course

In the lower course of a river, the level of the slopes is already almost zero, so the unevenness is small. For this reason the speed of the water is much lower than in the previous courses, even at first glance it seems static.

It is in its lower course, where the river deposits the greatest amount of materials that it drags, giving rise to alluvial plains.

At the same time, it is in the lower course of the river where lakes or sedimentary islands called deltas produced by the sedimentation of materials carried by the river can form.

It is in the lower course of the river where the different mouths of the river occur. These being its final stretch. This is where wide estuaries are usually formed, made up of a wide and deep mouth of the river and where the fresh water of the river mixes with the salty water of the sea.

References

1. Baird, DM (1965). Clacier and Mount Revelstoke National Parks: Where the Rivers are Born.

2. Jolley, R. (2008). Effects of Sedimentation on Productivity, Nutrient Cycling and Community Composition in Riparian Forests Associated with Ephemeral Streams at Ft. Benning, GA, USA. ProQuest.

3. Judy L. Meyer, Ph.D., University of Georgia; Louis A. Kaplan, Ph.D., Stroud Water Research Center; Denis Newbold, Ph.D., Stroud Water Research Center; David L. Strayer, Ph.D., Institute of Ecosystem Studies; Christopher J. Woltemade, Ph.D. (2007). Where Rivers Are Born: The Scientific Imperative for Defending Small Streams and Wetlands. Retrieved from Croametteinitiative. Retrieved from willametteinitiative.org/tools-resources/where-rivers-are-born.

4. Kathleen C. Weathers, DL (2012). Fundamentals of Ecosystem Science. Academic Press.

5. Likens, GE (2010). River Ecosystem Ecology: A Global Perspective. Academic Press.

6. WHERE RIVERS ARE BORN: THE SCIENTIFIC IMPERATIVE FOR DEFENDING SMALL STREAMS AND WETLANDS. (nd). Retrieved from Americanrivers. Extracted from americanrivers.org.

7. Where Rivers are Born: The Scientific Imperative for Defending Small Streams and Wetlands. (2003). Sierra Club.