My first exposure to rivers was the movie The African Queen (1951) when I was a child. Intrigued by the adventure and beauty of the unnamed East African waterway, I dove into The Adventures of Tom Sawyer as soon as I was old enough to read it, and have enjoyed uncovering bits of information about the world's rivers every since.
The longest river in the world is the Nile. Stretching 4,160 miles, from Ethiopia to the Sudan in North/East Africa, the river boasts far more than an acquaintance with Cleopatra, Egypt's last pharaoh (57 BC). Cleopatra would never have considered herself Queen of the Nile', however; the river was known to ancient Egyptians as Aur, meaning black' and Kem to ancient Greeks (also translating black'), both cultures named the mighty river after the black sediment left behind after frequent flooding. The river's current name comes from another Egyptian word, Nelios, which means river valley'. Multiple dams have been erected, eliminating the flooding problem in populated areas, but the river valley lives on. Home to more than 300 species of birds, 115 species of native fish, the fearsome African crocodiles, turtles, and baboons (to mention a few), the Nile River Valley is enormous. The Nile River Delta is estimated to drain 1,293, 000 square miles of land. The Nile is still a major source of transportation for the region, and a primary part of the areas agriculture.
Coming in number two, the Amazon is the Nile of South America'. An impressive 4,100 miles long (only 24 paltry miles shorter than the longest waterway), this river seems to have an acceptable consolation prize: it is the world's widest rivers, at times six miles from one side to the other. It is also responsible for 20% of the water entering the world's oceans from river sources. Running trough Brazil and Peru, the Amazon has literally thousands of sources, many of them 1000 miles in length themselves. The first European to travel the length of the river (1541-1542), Francisco de Orellana, named the river after a Greek tale about the Amazons, fierce women warriors. Encountering a similar band of women in his travels, and remembering the ancient story, he named the vast river for them, either as a warning to future travelers or as attribute to the spirit of the women. Snaking through the Amazon Rainforest, the river is home to an estimated 20-40 million species of animals. While the vast majority of these are insects (not so exciting for most of us), bird species number in the range of 3000, as do recognized fish species, and land animals number in estimated millions. All species haven't even been scientifically identified at this point. Some more well known of the animals are parrots, jaguars, gorillas and toucans, but the Amazon hosts some that are a little stranger than what we're used to here in the US. Rabbit-sized antelope, flying snakes and bird-eating spiders thrive in the special environment around the Amazon River, which is home to approximately half the animal life on Earth.
The Chang-jiang ("the long river"), or the Yangtze River, is the third longest river. While less known in the west, the Yangtze River stretches from the Qinghai-Tibet Plateau, in western China to the East China Sea, near Shanghai. A massive 3,964 miles long, the Yangtze drains an area equal to 695,000 square miles of land, located in nine different provinces of China. A major source of transport and commerce, the Yangtze, which goes by as many as half a dozen names in China, has been home to mankind for over 2000 yeas. Home to an almost uncountable number of species of animals, the Yangtze has several hidden jewels in the zoological world, including the Javan Rhino, one of the ten rarest animals in the world, and the Baiji Dolphin, previously thought to be extinct. Archeological research beginning in the 1970's reveals that the civilization growing up around this river may be the earliest civilization in the world, contrary to popular thought.
Number four on the "long rivers list", also of China, is the Huang He River, measuring 3,395 miles. Called the Yellow River due to the color of the silt carried downriver, the Huang He begins in the Kunlun Mountains in western China and runs to the Gulf of Bohai. Called the River of Sorrows, flooding is common here. In 1931 the Huang He provided the worst flooding in recorded history, taking 1 million lives in the flood and ensuing famine and disease, and leaving an estimated 80 million homeless. Once thought to be the site of the world's oldest population, the river has long been a source of transportation, commerce and fertile farmland. During WWll, Chinese soldiers broke levies on the Huang He to flood an area occupied by invading Japanese troops. The forces were thwarted, losing 900,000 men in the ensuing flood. Sadly, although the Yellow River once boasted a wide variety of fish, 30% are now believed extinct, and 2/3 of the river is too polluted for human use. Even so, the Huang He River is a life source for a myriad of wildlife.
Each of the world's four longest rivers has a uniqueness and majesty of their own. It's interesting to note that the longest river in North America, the Canadian river MacKenzie, comes in ninth place with a paltry 2,635 miles. The US doesn't rank until the Mississippi and Missouri finally appear in 14th and 15th places, measuring 2,350 and 2,341, respectively. It is also interesting to note that the oldest recorded civilizations seem to have developed around the world's longest rivers.