Rivers
 
You must have heard mythological stories about Ganga, Yamuna and Brahmaputra. These are some of the great rivers which form the lifeline of many Indian cities. By definition, a river is a body of flowing water restricted to a narrow channel by its banks. They originate as a stream in the higher areas and flow down through the plains before joining other larger water bodies like a sea or an ocean.
 
 How are rivers formed ?
When the Earth was created and when mountains and seas had just been formed, the falling rain-water formed zigzag paths while coming down-hill. Over the years, the continuous flow of water made these tracks deeper and wider. These streams of water underwent many changes and subsequently became rivers.
 
Today most rivers start from mountains. They get their water from the melting snow and glaciers. For example, the river Ganga originates from a glacier in the Himalayas called Gangotri. During the summer months, when the temperature rises, ice melts and the river Ganga flows down into the plains. It passes through many cities of northern and eastern India before falling into the Bay of Bengal.
 

Interestingly, a river does not move at the same speed all the time. Typically, a river flows very fast from its point of origin, but as it advances, it slows down. A river is slowest near the end of its journey, before it finally drains into other water bodies.

A flowing river carries a lot of sediments with it. This soil gets collected at the point where a river meets the sea or a lake. The place where a river meets the sea or ocean is called a delta. The sediments deposited by rivers make deltas very fertile. The largest delta in India is the Sunderbans.
 
 How did the word 'river' originate?
The word 'river' is derived from the Latin word 'ripa' meaning river bank. In the ancient times, a stream of water with definite banks was called a river.
 
Did you know?
Rivers are not just used to supply us with drinking water. They are also an important means of transportation of goods. Steamers and boats are plied in rivers to carry goods from one place to the other. Dams are constructed on rivers to accumulate water, and by making water fall from a height, electricity is generated. Also, logs of wood are transported from the hills to the plains through the rivers.
 
 Fundu Fact
River Nile of Egypt is the world's longest river. It runs for 6690 kilometres before flowing into the Mediterranean Sea. Crossing the length of the Nile once is equivalent to travelling from Jammu, the northernmost part of India to Kanyakumari, the southernmost tip and back!