- A river is a body of flowing water. Sometimes it rushes and rages. At other times, it flows slowly.
- About two-thirds of Earth’s surface is water, but most of it is sea water.
- Rivers and lakes contain freshwater, but they make up just 1 percent of all the water on Earth.
- We must rely on the water from the rivers and the lakes for freshwater.
- A river is always pulled by the Earth’s gravity from high down to a larger lake or to the sea.
- Water began from gases that formed around the Earth millions of years ago. The rain that fell on the mountains gathered in dips and cracks. It then began to flow as streams and rivers.
Stages of Rivers
- River has many stages from the start in the hills to its end near the sea. From the high ground, they run downwards, either to the lake or to an ocean. While running, rivers go deeper and wider. The starting point of the river is called the Source.
- A river may start with water from an underground spring or with the melting snow of glaciers high up in the mountains. As the water starts to flow down the steep slopes, it becomes a small stream and cuts a channel in the rock.
- As other streams called tributaries join the main flow of water, the river becomes wider, deeper and more powerful. This is known as the middle course of the river.
- A river may end its journey by flowing into a lake. It may flow into another river that travels to a lake or the sea.
Animals, Plants and Human
- At its start, a river is as full of energy, it tumbles over rocks and races along the ground.
- When a river flows over a ledge of hard rock, the water spills over the edge. This action creates a waterfall.
- The river carries fine mud and sand, known as sediment.
- Animals and Plants need freshwater, too. Plants thrive in and around them. Animals live in or close to the water. Humans could not have survived without rivers. So people often settle near rivers.
- We need water to drink and cook. Water is needed for cultivation to grow crops.
Longest River
- The River Nile is the longest river in the world. It is more than 4,160miles long. The Amazon is the second longest river in the world. It is so long that it flows through many different climates and types of vegetation.
River Floods
- Rivers can do a lot of damage. A river floods when too much water moves into this channel, and it cannot hold it all.
- Rivers may flood because of high tides, rain that is very heavy or that falls over many days, or a sudden temperature increase that melts ice and snow.
- If the flood is very severe, a river may carry a hundred times more water than usual, and it can destroy anything in its path.
- Dams and flood barriers protect people who live near rivers from the effects of floods.
River Pollution
- People allow the rivers to get polluted. Waste material pollutes our river water. Water pollution kills many kinds of plant and animal life.
- We must understand how important rivers are. We have to take good care of them. We need the rivers for ourselves and for all the wildlife.
- So, now it is time to protect our rivers.