Ep.23: The 10 Longest Rivers

August 18, 2023 Peter Jans

Intro

Hello and Welcome to this episode of the podcast, "The Mnemonic Tree", where we add a single mnemonic leaf to our Tree of Knowledge.

Today's episode will be on the 10 longest rivers in the world, and just like the 10 highest mountains there is a little conjecture amongst experts as to which river is the longest, the Nile or the Amazon?

This is complicated further by a myriad of other factors that can affect a rivers length.

So, to learn a little more on how they calculate this, we will begin with a summary from Wikipedia.

https://commons.wikimedia.org/wiki/File:ISS035-E-007148_Nile_-_Sinai_-_Dead_Sea_-_Wide_Angle_View.jpg

Wikipedia Summary

There are many factors, such as the identification of the source,[1] the identification or the definition of the mouth, and the scale of measurement[2] of the river length between source and mouth, that determine the precise meaning of "river length". As a result, the length measurements of many rivers are only approximations (see also coastline paradox). In particular, there seems to exist disagreement as to whether the Nile [3] or the Amazon [4] is the world's longest river. The Nile has traditionally been considered longer, but in 2007 and 2008 some scientists claimed that the Amazon is longer[5][6][7] by measuring the river plus the adjacent Pará estuary and the longest connecting tidal canal.[8] A peer-reviewed article published 2009 in the International Journal of Digital Earth concludes that the Nile is longer.[9]

Even when detailed maps are available, the length measurement is not always clear. A river may have multiple channels, or anabranches. The length may depend on whether the center or the edge of the river is measured. It may not be clear how to measure the length through a lake or reservoir. Seasonal and annual changes may alter both rivers and lakes. Other factors that can change the length of a river include cycles of erosion and flooding, dams, levees, and channelization. In addition, the length of meanders can change significantly over time due to natural or artificial cutoffs, when a new channel cuts across a narrow strip of land, bypassing a large river bend. For example, due to 18 cutoffs created between 1766 and 1885, the length of the Mississippi River from Cairo, Illinois, to New Orleans, Louisiana, was reduced by 351 kilometres (218 miles).[10]

These points make it difficult, if not impossible, to get an accurate measurement of the length of a river. The varying accuracy and precision also makes it difficult to make length comparisons between different rivers without a degree of uncertainty.

Extracted from: [https://en.wikipedia.org/wiki/List_of_river_systems_by_length]

https://commons.wikimedia.org/wiki/File:River_RP.jpg

Mnemonic

The 10 Longest Rivers Mnemonic – NAY MYY ORCA

(Picture your pet Orca whose name is Nay, whose job it is to measure all the longest rivers of the world)

1. Nile - Africa

2. Amazon - South America

3. Yangtze - China

4. Mississippi - USA

5. Yenisei - Russia

6. Yellow - China

7. Ob-Irtysh - Russia

8. Rio Grande-Parana - Uruguay

9. Congo - Africa

10. Amur - Asia

Five Fun Facts

1. The Congo Basin has about forty hydro-power plants and two dams.

2. A total of eleven different countries share the water resources of the Nile.

3. The Mississippi River was used as a boundary line for several states. The river has however shifted in certain places over time, leaving small pockets of the state over the other side of the river.

4. In China the Yangtze can be navigated by large ships for up to a thousand miles inland.

5. The Amazon has tidal waves in late winter which can be up to four metres in height and travel up to 13 kilometres inland.

Many people who have tried to surf the wave have been shocked. Why? Because the river’s current is so strong!

But honestly, I love rivers. So much so, I was watching a live stream earlier!

https://commons.wikimedia.org/wiki/File:Horseshoe_Bend_TC_27-09-2012_15-34-14.jpg

Three Question Quiz

Q.1. A river begins at a source or sources, follows a path and ends at a what?

Q.2. Which river has the largest discharge volume?

Q.3. Which river is the longest inside only one country?

Bonus Q. What did the river say when it was happily flowing down the plains when it all of a sudden hit a wall?

Mnemonic Recap

The 10 Longest Rivers Mnemonic – NAY MYY ORCA