After a long-lasting debate, the scientific community has reached an accord. The longest river in the world is the Nile, beating out the Amazon by a matter of just 40 miles. While this may initially come off as a crippling defeat for the Amazon, in reality, the South American linchpin has no more room on its trophy shelf.
There is little debate when it comes to the, far less speculated, widest river in the world. The Amazon takes the cake handily. During the dry season, from August to November, the Amazon river ranges between 2 and 6 miles in width. To compare, during the wet season at its widest point, the Nile stretches just 1.7 miles from bank to bank. Even more remarkably, during the wet season between December and May, parts of the Amazon swell to an impossible 25 miles in width.
To put some of these figures into perspective, consider the following: The Amazon river stretches just over 4,000 miles through the vast Amazon basin. With an average width of 4.5 miles during the dry season, the Amazon river alone covers some 18,000 square miles of land, an area comparable in size to Costa Rica. If one took all of the Amazon's hundreds of tributaries into consideration, the network covers an approximate area of 42,500 square miles, about the size of Bulgaria. During the wet season, when the floodplain is submerged, the Amazon and its tributaries take up over 135,000 square miles, roughly the area of Germany.
While the statistics only serve to reinforce its dominance, the Amazon is only the world's widest river when you consider average width. Although the Amazon is the standalone behemoth of rivers, according to which definition one abides by, the Rio de la Plata may take the cake for maximum width. The Rio de la Plata in South America is nearly 140 miles wide at it's "estuary", the point where it flows into the Atlantic Ocean, near Buenos Aires, Argentina.
An estuary is the point where a river collides with the body of water it's been flowing towards. An estuary is different from a delta. While a delta is the alluvial formation of split river paths and small islands, an estuary is generally a continuous body of water with no islands. Many bays are also estuaries. Estuaries are typically composed of brackish water, a mixture of sediment, freshwater from the river and salt water from the ocean or sea that it disperses into.
The largest estuary in the world is located at the mouth of the St. Lawrence river, where it drains the Great Lakes into the Atlantic Ocean. The estuary of the St. Lawrence river is 744 miles long and 90 miles wide. It's a bit larger than the country of Bangladesh, which is home to over 161 million people. Estuaries murk up the perception of the world's widest rivers, because there isn't a consensus over whether an estuary should be considered a part of the river itself, the destination it flows towards, or an independent body of water.
At the end of the day, it is difficult to objectively quantify the width of the world's rivers, as the results are entirely dependent on the season and the region's precipitation. One objective figure that could be considered river discharge, which measures the amount of water a river expels each second. If we include rivers that drain into the Amazon river, six of the top ten rivers by discharge are located within the Amazon basin. Many of them contribute to the Amazon river's unparalleled 209,000 cubic meters of discharge per second.
The top ten rivers by discharge in cubic meters per second. This list excludes rivers that drain into other rivers: