A river is a natural stream of water that flows to another water body such as a lake, ocean or another river. Rivers can be found on every continent but there are at least 18 countries that don’t have any river at all. Russia has the most number of rivers with around 100,000 while the United States has the oldest one which is ironically called the New River.
The world’s longest river is the Nile River at 6,853 kilometers long, followed by the Amazon River at 6400 kilometers in length. The third is the Yangtze River with a length of 6,300 kilometers while the Caño Cristales river in Colombia is referred to as the world’s most beautiful river because of its stunning multiple colors.
Check out our article detailing the “Top 10 Most Beautiful Coral Reefs in the World”
Types
Ephemeral Rivers
Whenever snow melts quickly or there is an exceptionally heavy downpour, it can result in an ephemeral river. The river’s temporary quick flow can be found in desert areas where flash flooding occurs on a very irregular basis. For most of the year, these rivers’ beds remain dry because the water table is below the surface and therefore, base flow does not happen.
Episodic Rivers
Although they are rare, episodic rivers are formed from run-off channels and found in areas with very dry climates. They may have some permanent areas, and they usually only flow fervently after very heavy rain. In the desert, episodic rivers are very important sources of water. They can also be thought of as seasonal or occasional rivers, and they are known as episodic because they only exist after an episode of a heavy downpour of rain.
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Exotic Rivers
Any river that flows through a very dry region is called an exotic river. Most commonly, exotic rivers flow through the desert and are found in places such as Saudi Arabia and the countries that surround it.
The Tigris and Euphrates rivers are perfect examples of exotic rivers, and they flow from the Persian Gulf into northern Iraq. Essentially, a river is called exotic because it stands out on the landscape, so a river that sits in the middle of an otherwise dry, barren region such as a desert is always called an exotic river.
Intermittent Rivers
These are rivers that have a semi-permanent nature and are known because of their seasonal flow. During wet periods when runoff is related to both heavy rain or a temporary rise of the water table, the rivers will flow fully. In the summertime, which is considered a dry period, the river bed may be dry because of a falling water table and reduced rainfall.
Mature Rivers
A mature river is not very steep and has a slow flow when compared to youthful rivers. Youthful rivers have several tributaries feeding into it, and they have less of a sediment deposit than youthful rivers. Examples include the River Thames, the St. Lawrence River, and the Ohio River.
