WATER ON EARTH

Introduction

-7 billion people on Earth

-So many contrasts of wealth and development between the countries but ONE thing in commmon: the need of water.

-Water consumption has been multiplied by 5 since 1950 while the world population has doubled.

KEY QUESTION:

Why did water become such a precious resource?

Layout:

1-Distribution/2-Use/3-Management.

I/ An unequal distribution

A/ Natural water resources

-Hydrosphere: 1400 million SqKm

EARTH WATER

Fresh water 3% Saline water/Oceans 97%

Ground

water

Surface waterIcecap and glaciers

Rivers Swamps Lakes

I/ Distribution

B/ The water cycle

This cycle is made up of four main parts:• evaporation • condensation • precipitation • collection

THE WATER CYCLE IN SHORT…

WORD BOXEvaporation:   Evaporation is when the sun heats up water in rivers or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river or ocean and goes into the air.

This cycle is made up of four main parts:• evaporation • condensation • precipitation • collection

THE WATER CYCLE IN SHORT…

WORD BOX

Condensation:    Water vapors in the air gets cold and changes back into liquid, making clouds. This is called condensation

This cycle is made up of four main parts:• evaporation • condensation • precipitation • collection

THE WATER CYCLE IN SHORT…

WORD BOX

Precipitation:  The process of precipitation is when so much water has condensed that the air can’t hold it anymore.  The clouds get heavy and water falls back down to earth in the form of rain, hail, sleet or snow.

This cycle is made up of four main parts:• evaporation • condensation • precipitation • collection

THE WATER CYCLE IN SHORT…

WORD BOX

Collection:  When water falls back to earth like in precipitation, it may fall back in to oceans, or rivers or it may end up on land. So, the cycle can start again!

I/ Distribution

C/ An unequal distribution

Look at the following map and locate:

-The areas that have plenty enough water

-The areas that lack water

I/ Distribution

C/ An unequal distribution

1-Look at the map (p 96 N° 2) and locate:

-The areas that have plenty enough water

The areas that lack water

2- As you’ve studied contrasts of development on Earth what link can you make between water distribution and development contrasts?

The areas that have plenty enough water are

-Northern America, Russia and Siberia, South America, Oceania and South-East Asia

-They correspond to humid climates ( heavy rain and monsoons)

-Water is sometimes solid and forms ice and snow

-It also corresponds to areas where there are large rivers

The areas that lack water are

-East Africa ( Ethiopia) and South Africa

-Northern Africa

-They correspond to dry climates

However, acces to water is not the same: let’s study this map

Percent of people with acces to water:Dark blue : over 95% of population has access to water  

Light blues 83 à 95% Yellow: 65 à 83%  

   Red: under 65%  

Dark blue : over 95% of population has access to water  

Light blues 83 à 95%

Yellow: 65 à 83%  

Red: under 65% 

II/ Water use

A/ How is water mainly used on Earth?

1- Introduce the document

Urban consumption

Industrial use

Agricultural use

Source : UNO 2003

II/ Water use

A/ How is water mainly used on Earth P 103

2-How is water used?

Urban consumption

Industrial use

Agricultural use consumption

Source : UNO 2003

II/ Water use

A/ How is water mainly used on Earth P 103

3-Give a precise example for each type of use

Urban consumption:leisure activities, cleaning,

hygiène,

Industrial use: to cool down power stations,cleaning, chemical products( solvent, diluent),paper production, energy production : geothermy, springs, hydroelectricity

Agricultural use consumption: irrigation

Source : UNO 2008

When studying water use in the world, we can notice When studying water use in the world, we can notice 2 sharp contrasts:2 sharp contrasts:

-First, It’s obvious Northern Countries ( MEDC’s) use more water than Southern Countries( LEDC’s).

Most MEDC’s use 100 cubic meters per capita per year whereas LEDC’s use under 500 on average.

-Then, the map shows MEDC’s use water for domestic use and industrial use, whereas Southern Countries use water mainly for agricultural purpose.

Indeed, agriculture is the most important economic sector in LEDC’s.

II/ Water use

A/ How is water mainly used on Earth P 103

4- Looking at the following map, comment on the distribution of drinking water on Earth

Urban consumption

Industrial use

Agricultural use consumption

Source : UNO 2003

Looking at the distribution of drinking water on earth, we can notice:

-First, in Northern Countries ( MEDC’s) more people have access to drinking water than in Southern Countries(LEDC’s).

-In some southern countries in Africa, it’s really hard to have access to drinking water.

-There are three reasons for this :

-Northern countries can recycle their water and purify it when it is polluted

-Southern countries don’t have enough money for water recycling plants

-In southern countires pollution is high because they accept all sorts of polluting indutries from the North.

B/Case study: water management in the Nile Basin

Work on the given worksheet

III/ Water: a resource which needs to be carefully managed

A/ Water for life and security: work on a text

This text is extracted from a conference held in Barcelona in the 2004 Universal Forum of Cultures organized by Barcelona's local council, the regional government (the Generalitat de Catalunya), the Spanish National Government and UNESCO.

The official aims of the 2004 Universal Forum of Cultures included support for peace, sustainable development, human rights and respect for diversity.

B/ What are the challenges for the future?

1- Allow an easier access to water to a larger spectrum of people on Earth

-by building wells in the poorest countries

-by building dams to launch irrigation projects

-by building more desalination plants

-By building more water-treatment plants ( Vivendi in France)

2- Avoid conflicts over water

-In 1997 the UN has made a charter for some International rights for water but it has not been signed by a lot of countries

3-Preserve water as a precious resource-Water recycling ( but 180 billion dollars would

be needed to enforce this in Southern countries between 2010 and 2025)

-Use underground water and rain-Improve irrigation: less sprinkle irrigation ( par

aspersion) and more drip irrigation ( goutte à goutte)-Education to stop wasting water

4- Some international meeting are organized to debate over water use and water management in the world today

-In 2000 in the Hague ( La Haye – Netherlands)

-In 2003 in Kyoto ( Japan)

-In 2006 in Mexico

-In 2007 in Nairobi ( Kenya)

CONCLUSION

KEY QUESTION:

Why did water become such a precious resource?

We’ve seen that if water is abundant on Earth, it’s a very unequally distributed resource.

In the richest countries water is sometimes wasted and becomes very expensive whereas in the poorest countries, water is rare and a source of conflict. So, international water management is at stake today

Branching out

Access to water once again witnesses the North/South divide. So, we can think that a better development would ensure a better access to water.