How are humans affected by changes in water supplies?

For a two mark exam question what is this cartoon suggesting about water supplies?

Lesson objective:• Locate the Sahel region• Define the term desertification • Understand how changes in water supplies

can impact on people and ecosystems

The Sahel is a narrow belt south of the Sahara desert. It stretches from the West Coast of Africa from Mauritania to the western boarder of Sudan.

The countries most affected are Mali, Niger and Chad.The area most affected are areas South of the Sahara Desert and North of the Savannah grasslands

MaliNiger

Chad

Mauritania

Sudan

Ethiopia

Where is the Sahel located?

Describe the rainfall pattern in the Sahel region between 1970 and 2004 (2 marks)

DESERTIFICATION

Use the cards you have been given to create a flow diagram to describe why the Sahel region suffers from desertification

Why does the Sahel suffer from desertification?

DESERTIFICATION

Increase in population Increase in cattle

Deforestation for fire wood Grassland grazed more intensively

Roots no longer hold soil together Roots may be eaten as well as grass

Leaves no longer protect soil from weather Less vegetation means less protection from weather

Loose top soil blown away by wind(Soil Erosion)

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Loose top soil blown away by wind(Soil Erosion)=

DESERTIFICATION

Lake Chad, once a huge lake straddling the borders of Chad, Niger, Nigeria and Cameroon, has shrunk by 95% since the mid 1960s.

The region's climate has changed during that time, with the monsoon rains which previously replenished the lake now greatly reduced.

A recent study blamed human activities combined with local weather changes, not global warming. It said overgrazing had destroyed the savannah vegetation which itself influenced the weather patterns.

As the climate has become drier, the demand for water to irrigate food crops has increased – quadrupling between 1983 and 1994 - depleting the lake further.

Nine million farmers, fishermen, and herders in the region now face water shortages, crop failure, livestock deaths, collapsed fisheries, soil salinity and increasing poverty.

A closer look at Chad- How have people been affected?

Plenary – Gimmee 5!

5 – Reasons for desertification4 – Countries in the Sahel region 3 – Causes of water scarcity2 – Rivers that provide ¾ of water consumed

nationally1 – Weather pattern that has been influencing

the