Test

Question 1

Outline reasons why salinisation of soil occurs

Answer 1

Salinisation means the accumulation of salts in soil and it can happen as a result of both natural and human processes
• Over long periods of time, soil minerals are weathered and subsequently release salts. Salts are also added via dust and
precipitation
• In areas of high temperatures and low precipitation salinisation
occurs naturally due to high levels of evaporation. As water is
drawn up through the soil it leaves behind any salts that were
dissolved within it.
• Human causes include excessive groundwater extraction which can
lead to saltwater intrusion, whereby seawater moved into freshwater
supplies.
• Irrigation can also lead to salinisation where waterlogging causes the
water table to rise bringing dissolved salts to the surface
Evaporation then leaves a crusty layer of concentrated salts on the surface

Question 2

What are features of stage 1 of the DTM

Answer 2

• High fluctuating birth and death rates

- Population growth is small

Question 3

What are some reasons for the stage 1 of the DTM

Answer 3

Birth rate factors
• Limited family planning
• High infant mortality so people have more children so some survive
• Children are a source of income
• Some religions encourage large families

Death rate factors
• High incidence of disease
• Famine
• Poor water and sanitation
• Poor health facilities

Question 4

What was Malthus’ philosophy

Answer 4

“The power of the population to increase is

greater than that of the earth to sustain it.”

Question 5

What is some evidence that can support Malthus’ theory?

Answer 5

resource depletion

environmental damage

economic decline

Regular famines that occur in the Sahel

Wars that occur over food, water and energy

Water scarcity in the middle east.

Question 6

What was Esther Boserup’s philosophy?

Answer 6

“necessity is the mother of invention”