Rivers provide us with food, energy, recreation, transportation routes, and of course water for irrigation and for drinking. But where do they start and where do they end?
Rivers begin in mountains or hills, where rain water or snowmelt collects and forms tiny streams called gullies. Gullies either grow larger when they collect more water and become streams themselves or meet streams and add to the water already in the stream
The World's Longest Rivers
Nile 4,160 miles
Amazon 4,000 miles
Chang Jiang 3,964 miles
Mississippi-Missouri 3,710 miles
Ob-Irtish 3,362 miles