HOW ARE RIVERS FORMED? - ENVIRONMENT - 2025

Rivers are formed when they receive a continuous source of water such as a spring. A river is a natural stream of water, which flows through a bed from a higher place to a lower one.

It has a considerable and constant flow, and flows into the sea or a lake. It can also flow into another larger river, and in this case it will be called a tributary. If the river is short and narrow, it is called a stream or stream.

The rivers are divided into upper course, middle course and lower course. In the upper course is where they are born, the middle course is the route of the river where it still has enough force of flow and remains more or less straight; and in the lower course is where it begins to lose out and form curves before reaching its mouth.

There are several ways in which rivers are formed through the passage of time and geological and meteorological phenomena. You may also be interested in where the rivers are born.

Ways in which rivers can form

Rain

Rivers receive their water from different sources. Usually these sources are related to rain.

The rains that are produced by the condensation of the water in the oceans, form the clouds that move towards the continents and thus the precipitations are produced.

When precipitation falls, there is a point where the absorption capacity of the soil becomes saturated. The water then works its way through small grooves in the ground.

In high areas, these grooves sculpted by the action of water are due to the rain or thaw found in the upper parts of the mountains.

The furrows are getting deeper and deeper through erosion. Many of these furrows do not have a constant channel, but are filled with water in rainy seasons or intermittently by the melting of snow in times of heat.

Channel formation

Luján River

As they do not have a constant channel, they are not considered rivers, but are called torrents or streams. The process of wear of these furrows throughout the geological history of the earth, has made them deepen to a layer of permanent saturation.

In this way the transported water remains in the river bed and does not leak. At the source of the river is where the route of this begins. It can begin with a spring or by groundwater, by the melting of glaciers or by the same rain.

Rain often runs down the mountain slopes and can form surface streams. If furrows are made that erode the soil and there is enough precipitation, these can form a riverbed.

For this to happen, the land through which the river descends has to be saturated with water and be impermeable.

Springs

Another way to form a river is through springs. A spring is a source of natural water that springs from the ground or between rocks.

Water from rain or snow penetrates an area and appears in an area at a lower altitude. When the spring flows into an impermeable surface, the water is not filtered again and this creates a furrow that becomes the river bed. The rainwater feeds the spring which in turn feeds the river at its source.

Aquifers

In addition to springs, many rivers are fed by aquifers. An aquifer is a mass of permeable rocks that allows the accumulation of water that passes through its pores or cracks.

When the aquifer reaches a saturation level, the water comes out through its pores and if the ground is impermeable it descends in the form of furrows.

Groundwater is an important source of river water that does not depend on rainfall to maintain a constant flow. However, it is necessary that from time to time rainfall refills the groundwater.

Thaw

Finally, rivers can be formed through the melting of glaciers in the high mountains. As we have commented before, the water produced by the thaw creates furrows along the mountainside.

The soil becomes saturated with water and we reach the impermeable layer, and we obtain the furrow through which the riverbed will pass.

The rivers of the glacial regions tend to have a greater channel in the summer months, since this is when the thaw occurs.

In the winter months, the precipitation freezes in the higher areas, forming glaciers, which will melt again when the high temperatures arrive.

Union of streams and streams

If you look at powerful rivers like the Amazon or the Nile, they not only have one source, but they have dozens of origins. So several streams meet and streams join to form larger rivers.

For example, in the case of the Amazon, its source is not yet clear. Geographers consider the source of the river as the most distant point upstream that supplies the largest volume of water.

However, the amount of water provided depends on the time of year, so it is not feasible to consider a single point as the source of the river.

To get a glimpse of which is the branch that supplies the greatest volume of water, data on the flow of the water would be needed over a fairly large period of time.

Hydrological cycle

Finally, rivers are also defined as natural drainage lines for excess water found on the earth's surface.

The destination of rivers is always the ocean, which is what provides rainwater, which in turn forms rivers on the earth's surface.

This situation is known as the hydrological cycle. And through it we can ensure that every drop that belongs to a river has come out of the ocean, and will return to it a long time later.

References

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