| What is water?
|
|
|---|
|
Water is a very important substance, as it makes up the larger part of an organism's body. But what exactly is water? Inside the body of a human being there is a skeleton, which makes your body solid and makes sure you can stand up without falling apart. Water is also a kind of skeleton. It consists of tiny particles, the atoms, just like every other substance on earth. One of these atoms is called hydrogen and the other is called oxygen. As you probably know the air that we breathe also contains oxygen. One particle of water is called a molecule. When lots of water molecules melt together we can see the water and drink it or use it, for instance to flush a toilet.
|
| In what states (phases) can water be found?
|
|
|---|
|
Water exists in three states: solid, liquid and gaseous. At a normal temperature of about 25oC it is liquid, but below 0oC it will freeze and turn to ice. Water can be found in the gaseous state above 100oC, this is called the boiling point of water, at which water starts to evaporate. The water turns to gas and is then odourless and colourless.
How fast water evaporates depends on the temperature; if the temperature is high, water will evaporate sooner.
|
| How much freshwater is available?
|
|
|---|
|
Of all the water on earth, which is 97,14% of the total amount of surface water, only 2,59% is freshwater. Of this 2,59% another percentage is trapped in ice caps and glaciers, which is about 2%. The rest of the freshwater is either groundwater (0,592%), or readily accessible water in lakes, streams, rivers, etc. (0,014%).
|
| How much water is suitable for drinking water?
|
|
|---|
|
From the quantities that came up in the questions listed above, one can conclude that less than 1% of the water supply on earth can be used as drinking water.
|
| What causes fresh water shortages?
|
|
|---|
|
There are four different causes of water scarcity: a dry climate, drought (a period in which rainfall is much lower and evaporation is higher than normal), drying of the soil due to activities such as deforestation and overgrazing by livestock and water stress due to increasing numbers of people that rely on limited levels of run-off.
|
