Unit 3

WATER

1- Where is water found?

- On Earth: 71% of the Earth’s surface is covered by water (salt water is 97%, fresh water just 3%).

Activities

Exercises 1 and 2 on page 25.

2- What are rivers?-River source

-Tributaries

-Basin

-Flow (depends on the season)

The importance of rivers

-Transport

-Water supply: Canals, reservoirs

-Electricity: dams, power stations

Activities

Exercise 1 on page 26

3- What are oceans and seas?

They hold almost all the world’s liquid water, that is salt water.

Salinity is different depending on if the sea is warmer or colder.

Warm = + salt

Cold = - salt

The importance of oceans and seas

-Food

-Raw materials

-Energy

-Tourism

-Transport

4- What are currents, tides and waves?

Map of ocean currents

Ocean currents

Tides

Waves

Activities

Exercise 1 on page 28.

5- What are lakes?

Different terms:-Lake-Lagoon (small)-Inland sea (salt water)

Different origins:-Precipitation-Rivers or groundwater-Glaciers

Activities

Exercise 1 on page 29.

6- Where are groundwater and glaciers found?

GROUNDWATER. Aquifers.

Hot and cold springs

The importance of groundwater

-Drinking water

-Source for rivers and lakes

-To grow plants

Glaciers

Icebergs

Homework

Activity 1 on page 30.

7- What problems are related to water today?

WATER CONSUMPTION AND

DISTRIBUTION

-3% Fresh water -> 0,014% available

-Increase in population -> increase in

consumption

-Bad distribution

-Consequences: droughts or floods

Water pollution and acid rain

Activities

Exercises 1 and 3 on page 31.

Work at home

Exercises 1, 4 and 5 on pages 32-33.