Please enable JavaScript.
Coggle requires JavaScript to display documents.
Theme 3 Chapter 4: Desertification - Coggle Diagram
Theme 3 Chapter 4: Desertification
Key words
Sahel
Semi-arid region of North Africa
to the south of the Sahara desert
Drought-resistant
Plants that are able to survive long periods with below average rainfall
Desertification
When the climate of a dry region
becomes even drier
Rainwater harvesting
The collection and storage of rainwater
Chapter Objectives
2.To what extent does human activity contribute to the problem of desertification?
3.How can environments vulnerable to desertification be managed?
1.What are the physical processes operating in hot semi-arid regions that make them vulnerable to desertification?
3.How can environments vulnerable to desertification be managed?
1.What are the physical processes operating in hot semi-arid regions that make them vulnerable to desertification?
2.To what extent does human activity contribute to the problem of desertification?
causes of desertification
human
Farmers allow their goats to overgraze shrubs, and vegetation is killed
Trees and shrubs are burnt to clear land for farming or urbanisation
Trees are cut down for firewood for cooking
Commercial farms use the land so intensively that the soil is quickly worn out
physical
Annual rainfall totals are gradually falling
The rain in the wet season is unpredictable and can be very heavy, causing soil erosion
Less vegetation means less water is returned to the atmosphere by evapotranspiration
climate change
less rainfall & increased drought
vegetation dies
soil exposed to wind and rain
increased risk of soil erosion
desertification
Population growth
more animals reared
overgrazing
vegetation cover removed
soil exposed
increased risk of erosion
desertification
more land needed for crops
over cultivation
vegetation cannot re-establish itself
soil exposed
increased risk of erosion
desertification
more energy needed for lifestyle e.g. cooking
deforestation
vegetation cannot re-establish itself
soil exposed
increased risk of erosion
desertification
