Grade 4 Water Term 4 Flashcards
Why can’t we use water from the ocean
It is salty water, not fresh
What is the water cycle
Water constantly moves from the sea to the air and from the air back to the ground
What is underground water
Rain soaks into the ground and is stored in the ground as underground water
What are wetlands
When the level of underground water reaches the surface of the land it causes a wetland. Some wetlands are always under water, others are only wet during rainy season
How are rivers and streams made
Sometimes underground water causes a natural spring, this is the start of a stream. Streams flow out of springs and wetlands and join up to form a river
What is a lake
A lake is a natural area of water on the surface of the ground
Why do we need to store water
Our fresh water comes from rainfall. We don’t get rain all year round, so we need to store water for the dry times
How can we store water
Dams
Water tanks
Buckets and pots
How is a dam built
A wall is built across a river, and river water collects behind the dam wall.
How do people get water in South Africa
From a river Through pipes and taps From a borehole From a dam From a communal tap From a truck
How do most South Africans get their water
From taps
How is water stored in towns
In a reservoir
How does water get polluted from waste
People use the bushes as toilets and rain washes this into rivers
People use the river to wash themselves
People throw rubbish into the rivers
How do factories and farms pollute water
Factories use water and this water often has poisons dissolved in it. Sometimes the water is put back into rivers and dams
Farmers use fertilisers and chemicals, which go into the soil. heavy rain can wash the soils into dams and rivers
What are the 2 types of waste water
Great water ( water from our baths and sinks Black water ( water from our toilets)
