1. Topic 4.1 – How Humans Use Water
Fresh and Salt Water Systems

2. Direct vs. Indirect Water Usage
Direct is what you use in your every day life
Indirect is not water that you use personally, but the benefits you get from water being used in industry
Example: You drink out of plastic bottles – the plastic industry uses a TON of water to make the bottles.

3. Where do we use the most water?
1. Agriculture
2. Industry
3. Domestic

4. Agriculture
Agriculture uses the most water by people all around the world.
Of all the water we use, 73% is used in agriculture.
Irrigation is important to get food.
Irrigation brings in money for countries
Irrigation helps to provide jobs for people

5. Problems
Over-irrigation of the soil can dissolve salts in the soil and cause them to show up on the soil
Plants don’t grow in salty soil
Irrigation depletes groundwater supplies

6. Irrigation

7. Industry Of all the water we use on Earth, 22% is used for industry
Industry uses water for:
Coolant
Solvent
Washing
Diluting pollutants before releasing them into the environment

8. Different products require different amounts of water
The plastic industry uses a TON of water
Industry provides jobs, products and services

9. Domestic Domestic simply means: use in the home.
5% of total water use is used in the home
In Canada we have clean water piped into our homes… this is not the case in several countries where they may have to walk for miles to get fresh water.

10. Human Activities Impact Water
1. Factories
May add dangerous chemicals to the water or create thermal pollution
2. Power Stations
Put warmer water back into lakes
3. Runoff from farmland and cities
4. Sewage
5. Oil Spills
6. Habitat Destruction

11. Topic 4.2 – Measuring Impacts
Fresh and Salt Water Systems

12. Giardia Giardia is the micro-organism that causes beaver fever
Sometimes this can get into our drinking water
It can be controlled by proper chlorination but it can sneak through.
WE NEED TO MONITOR (Observe and check) regularly

13. Self – Directed Exercise
1. What sorts of things would scientists monitor water for? (pg. 401)
2. Why would we want ongoing monitoring of our water? (pg. 401)
3. At certain times of the year, more chlorine is used to purify our water. Do you think we should be doing this? Why or why not? (pg. 402)
4. Name one success story for cleaning up a polluted water source (pg. 403 – Thames River in England)