7/27/2019 4 - Water World

1/3

Water World

Water World

What is the impact of insufficient water supply on humans?

E.g. the Sahel, North Africa

Why are there water shortages? What are the effects of the water

shortages?Unreliable rainfall The Sahel region

receives very low rainfall

Surface runoff Much of the rain itreceives is lost through surface runoff,

when it comes in torrential downours.

Wealth Many of the countries in Sahel

are !E"#$s so cannot afford to ie water

to laces that need it.

Population growth The oulation is going

u very fast so there are more eole

demanding water.

Climate change %s ma&ing rainfall less

relia'le in the area

Droughts #auses rivers to dry u. This

can affect farming and food suly and

therefore lead to famine.Desertification With less water and

grass for animals, land is overgra(ed. This

can lead to lants dieing, soil erosion and

the area 'ecoming a dessert.

What are the effects of global warming on semi arid areas

E.g. the Sahel, North Africa

Effects of the environment Effects on humans)reciitation in the semi*arid Sahel region could

fall 'y +-. This would effect lant life.

"ue to changes in reciitation less, although

with heavier 'ursts/ will reduce cro roduction

and reduce food sulies.

The ris& of flooding and coastal erosion would

increase.

%ncreases in temerature could see the increase

of diseases li&e Malaria.

As glo'al warming increases fragile ha'itats may

not survive and 'etween +*0- of secies in

Africa could face e1tinction.

2amine and malnutrition will increase.

"ue to de't in many countries in Africa, they have

choed down forests to grow more cros to sell.

"roughts will cause 3desertification$, changing

fertile land into desert.

7/27/2019 4 - Water World

2/3

Water World

How do humans cause water pollution?

Agricultural:2ertilisers are washed into rivers. This can cause river lants to grow

4uic&ly, which ta&es u all the o1ygen in the river. This can &ill fish in the river.

Domestic:Sewage can 'e washed into rivers. This ollutes the water and &ills many

organisms.

ransport:Salt and materials can 'e washed into rivers from roads. This can harm

the fish and lant life.

!ndustrial:)ower stations can wash chemicals into the river. This will affect the

water 4uality and ma&e it very dangerous to humans and animals.

How do humans interfere with water supplies?

Deforestation choing down trees/: This can reduce intercetion and can lead to

increased surface runoff and flooding

Urbanisation the growth of cities/: This leads to a reduction in infiltration. %t also

has imermea'le surfaces, such as roads and car ar&s, so surface runoff increasesand floods can occur.

"#er abstraction of ground water: The water ta'le can fall and this can cause

ground su'sidence.

Cloud seeding: This increases reciitation 'y heling clouds to form. Although can

reduce rainfall in other areas.

$anaging water supplies: he Aswan Dam% &gypt 'a large scale

pro(ect)

The Aswan dam was a large scale ro5ect "ams are used to regulate the flow of rivers.

Advantages "isadvantages. Water can 'e used to irrigate

farmland all year round.

More land can 'e irrigated.

With water always availa'le two or

three cros can 'e grown each year.

These can 'e sold for a rofit to

ma&e Egyt richer.

The dam roduces electricity for

villages, cities and factories.

6illages are safer from flooding as

the level of the water can 'e

controlled.

There are more factories, more

tourism and more fishing. This

means there are more 5o's.

7+, eole were forced to leave

their homes 'ecause the villages they

lived in were ermanently flooded when

the dam was 'uilt.

2armland has also 'een ermanently

flooded, including the land of the

traditional sheherds.

No more silt soil/ is deosited so the

farmland 'ecomes less fertile.

2ertilisers have to 'e added to the

soil. These are e1ensive.

2ertiliser is washed into the 8iver Nile

causing ollution.

Water snails cause a disease called

9ilhar(ia. 2lood waters usually wash

the snails out to sea 'ut now the dam

has 'een 'uilt there are more snails

and so more disease which can &ill

eole.

7/27/2019 4 - Water World

3/3

Water World

$anaging water supplies: WaterAid% *hana 'a small scale pro(ect)

WaterAid is an +*" Non :overnmental ;rganisation #harity/

N:;$s use appropriate technology. These are schemes to meet the needs of local eole

and the environment in which they live.

Many eole in rural :hana are forced to drin& muddy dirty water.

Animals drin& from the same water. it also usesafforda'le materials which can 'e sourced locally.