Rivers and the Water Cycle

The Water Cycle

Where do rivers start? Most rivers start in the mountains because lots of rain falls there. Some rivers start as springs. Others start in marshy areas. The place where a river starts is called its source.

Where do rivers flow? The beginning of a river is usually called a stream. As streams flow downhill they meet with other streams to form larger rivers. Rivers flow downhill to the sea or a lake. This is because of a force called gravity.

The upper course In its upper course the river flows quickly. You get waterfalls. It wears away the rock around it and cuts a V- shaped valley. This is called erosion. The force of the water can move stones, pebbles and soil… ….and sometimes even boulders.

Reservoirs Dams are often built across rivers to make man made lakes called reservoirs. The water from reservoirs is pumped into peoples homes and to factories.

The middle course As the river flows downhill the valley becomes wider. It flows more slowly. Settlements grow on the banks of a river.

The lower course As the land becomes flatter the river meanders and often floods. Floodplains are usually very fertile, though they are often marshy.

Floods Floods can cause tremendous damage to the land and buildings People often lose their lives in floods.

Industry Factories are often located near rivers. This factory needs a lot of water for its cooling towers.

The lower course As a river approached the sea, it is wide and flows through flat land. Ships can navigate quite far up wide rivers. The ships could carry passengers or cargo.

The estuary You often get mudflats near the mouth of the river. Some plants grow well on the mudflats and they often attract wildlife. People often sail their boats in these estuaries.

The mouth of the river At the river mouth there may be harbours and or docks. These may be for fishing boats, cargo boats or ferries. Anchoring in the river means the boats are safe from rough seas.