We all need water to drink.
We use water for washing and cooking.
We use it in gardens and swimming pools.
It falls from the clouds as rain or snow.
All living things on Earth need water.
We wash our bodies with water.
We bath our pets in it.
We use it to cook with.
We swim and play in water.
We clean things with it.
We use it in our gardens and farms to the plants don't die. Plants are living things.
Some of our food lives in water, where many fish and other creatures live. Plants such as seaweed grow under the water.
We use water to take people and things in boats that go from place to place across oceans or along a river.
The water cycle
The sun shines onto areas of water, warming it up and it rises into the air as a gas called water vapour. This process is called evaporation. When water vapour in the air cools, it changes back into droplets of water. The tiny droplets gather together to make a cloud. Eventually, the droplets in the cloud fall to earth as rain or snow. It evaporates again and becomes water vapour and so on. This is called the water cycle because it goes on continuously: water never stops moving.
Go here for an animation of the water cycle.
Evaporation also occurs from plants. Moisture from the surface of leaves warms and changes into water vapour.
Fresh water for us
Rain or snow falls and ends up in lakes, rivers and the seas. Rivers, streams and most lakes are fresh water. Large dams are built to collect rain and other fresh water for human use. These are called reservoirs.
Some rivers are frozen. They are called glaciers (say glay-see-ers). Glaciers are frozen fresh water. Sometimes a huge mass of glacier breaks away and floats out into the sea. Then it is called an iceberg. An iceberg is frozen fresh water.
Water in the oceans
Most of the water on Earth is in the oceans, and this is salt water. The salt comes from rocks that the water has washed over in rivers and streams on its way into the sea.
Water in Australia
Australia is the second driest continent. In Australia there is a combination of low rainfall and a very high evaporation rate of water because of the sunshine. Even though they live on such a dry continent, Australians use a lot of water. About 19 million megalitres of fresh water is used in Australia each year. Most of this (about 70%) is used for agriculture, especially irrigation, to grow food and other products consumed in Australia and exported. Households use about 8%.
Some more facts about water
75 % of the Earth is covered with water.
97 % of Earth's water is in the oceans.
Only 3 % of the Earth's water can be used as drinking water.
75 % of the world's fresh water is frozen in the polar ice caps.
Water expands (takes up more space) when it freezes.
Raindrops are not tear shaped. The shape is more like that of a hamburger bun as they fall from clouds.
A person can live without food for more than a month but can only live without water for about one week.
Water boils at 212 degrees Fahrenheit or 100 degrees Celsius.
Water freezes at 32 degrees Fahrenheit or 0 degrees Celsius.
About two thirds of the human body is water and 70% of the skin is water.
Pollution is something which spoils or dirties a place or a thing. Water pollution occurs when a body of water is affected, in a bad way, by the addition of large amounts of a material. That material might be oil, garbage, animal wastes, fertilisers and other chemicals, sewage or litter.
Petroleum often pollutes water in the form of oil. Oil spills from ships and super-tankers, and from off-shore oil drilling operations cause pollution. Oil and petrol that leaks from cars and trucks also washes off roads and into waterways through stormwater drains.
Oil forms a thin layer on top of water and act like a lid on the surface and the water. Animals and plants living in the water can't breathe, the oil coats the feathers of water birds, and the fur of animals that swim in the water, causing them to become sick and, if there is a great amount of oil on their bodies, to die. Even the insects that live on the surface of the water are badly affected. Fertilisers
Fertilisers Nutrients in fertilisers cause excessive growth of plants and algae which takes oxygen and light from water animals Fertilisers contain nutrients such as nitrates and phosphates that help plants to grow. That's why farmers use them. When fertilisers are washed into rivers and streams the nitrates and phosphates cause excessive growth of water plants. The plants clogs the waterways, use up oxygen in the water, and block light to deeper waters. This is harmful to the fish and other invertebrates that live in water because it make it hard for the animals to breathe.
Pollution of waterways is also caused when silt and soil washes off ploughed fields, construction and logging sites, and from river banks when it rains.
Sewage and other organic pollutants
When material such as leaves and grass clippings, and waste from farm animals enters the water, it rots and breaks down and uses up the oxygen in the water. Many types of fish and other aquatic animals cannot survive. Organisms such as bacteria and viruses enter waterways through untreated sewage in storm-water drains, run-off from septic tanks, and from boats whose owners dump sewage into the water. These microscopic pollutants cause sickness in people and in animals that drink or live in the water.
Chemical pollution entering rivers and streams causes great destruction. The chemicals can come from factories, construction sites, mining operations, and from homes when people pour chemicals down the sink or down the toilet.
Floating plastic is ugly, and harmful to the environment. Plastic rubbish is not biodegradable (it doesn't rot away after we have used it) It can choke animals that try to eat it, and drown those that get tangled in it.
When people drop litter such as plastic and cans, food wrappers and cigarette butts, they can be washed by the rain into rivers and other waterways through stormwater drains in the streets. At the beach, it is important that people take home their litter or put it into garbage bins at the beach so that it doesn't get into the sea.
How many ways can you think of to help keep pollution out of the water?
How we use water
People use water for many things. In fact, we can't live without water!
Most importantly, we need to drink water. Living things need water or they dry out and die. Animals, including people, can go longer without food than without water. Water passing through our body systems keeps our inside parts working and in good health, and washes out impurities. Because water passes through our bodies we need to keep drinking water.
Wetlands are important places in the world. They are places where the water stays on the surface and does not drain away. Wetlands help filter water, removing dirt. They help protect coastlines from erosion and the effect of storms. They can help control flooding by soaking up heavy rainfall and releasing it slowly. Many animals and birds depend on wetlands for survival.