3.6 Causes and impacts of soil erosion

Question 1

Soil erosion

Answer 1

the wearing away of the topsoil by the action of wind or water

Question 2

the causes of soil erosion

Answer 2

human cause-
* removal of natural vegetation by-
* over cultivation
* overgrazing

natural cause-
* water erosion
* wind erosion

Question 3

Overcultivation

Answer 3

ploughing breaks the soil into smaller and lighter particles. These are more easily carried away by wind.

Question 4

Overgrazing

Answer 4

• livestock reduces the vegetation to nearly ground level, sometimes leaving no roots to hold the soil.
• Animals trample down the plants and their hoofs compact the ground.

Question 5

Wind erosion:

Answer 5

• damages land and natural vegetation by removing soil from one place and depositing it in another
• deforestation increases the chance of soil getting eroded by wind.

Question 6

Water erosion

Answer 6

• heavy rainfall carries the particles away.
• Excess run-off water that can’t be absorbed by soil transports the soil from that area;
• Soil compaction reduces infiltration;

Gully erosion (volume of water erodes local soil further) forms deeper and deeper crevices.

Question 7

the impacts of soil erosion

Answer 7

• loss of, habitats/biodiversity
• desertification
• silting of rivers
• displacement of people
• malnutrition/ famine

Question 8

loss of habitats

Answer 8

plants cannot grow
life cycle distrubed
reduction in plant or animal populations

Question 9

desertification

Answer 9

• the process by which fertile land becomes desert.
• Severe droughts lead to migration of the whole community.
• Risk of famine and malnutrition, leading to lesser food source.

Question 10

silting of rivers

Answer 10

flooding occurs as water bodies can’t hold excess water (space taken up by silt).

Question 11

malnutrition and famine

Answer 11

plants cannot grow / crop failure;
livestock death / livestock can’t graze or feed
food shortages