Desertification Flashcards
What is desertification?
Desertification is caused by both natural factors and human activities.
It refers to the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture.
What percentage of the world’s population is threatened by desertification?
Approximately 20% of the world’s population.
This indicates a significant global issue affecting millions of people.
True or False: Natural causes of desertification cannot be worsened by human activity.
False.
Many of the natural causes may be made worse by human activity and climate change.
Fill in the blank: Desertification can be exacerbated by _______.
human activity and climate change.
This highlights the interconnectedness of natural processes and human influence on the environment.
What is a consequence of soil erosion?
Loss of nutrients
Nutrient loss affects plant establishment and growth.
How have rainfall patterns changed?
Less predictable, leading to drought
Drought causes vegetation to die due to lack of water.
What effect does reduced vegetation have on soil?
Decreases nutrient addition through decomposition
Dead organic matter contributes nutrients to the soil.
What is the impact of short, intense bursts of rain?
Increased surface runoff and soil erosion
Short bursts of rain do not allow for proper soil absorption.
What does overgrazing lead to?
Loss of vegetation
High animal numbers prevent land recovery.
What is the result of over-cultivation?
Depletion of soil nutrients
Crops take up nutrients, leaving none for future vegetation.
What is a consequence of deforestation?
Increased soil erosion
Deforestation removes shade and roots that bind soil.
How does population growth affect land use?
Increased pressure to raise more animals and grow more crops
More people lead to higher demands on land resources.
What are the natural causes of desertification?
soil erosion, rainfall patterns and reduced vegetation
What are the human causes of desertification?
over-grazing, over-cultivation, deforestation and population growth
What is the main goal of strategies to reduce the risk of desertification?
Halting and reversing desertification means tackling the causes.
Name one method for water management to combat desertification.
Contour stones or bunds can be used to increase infiltration.
What is the purpose of earth dams in desertification strategies?
Earth dams can be used in the wet season to store water.
How does drip irrigation contribute to reducing desertification?
Drip irrigation can be used to water crops more efficiently.
List two aspects of education that can help reduce desertification.
- Sustainable farming methods
- Family planning to reduce population growth
What does agroforestry combine?
Agroforestry combines agriculture with forestry.
How does agroforestry help to reduce deforestation?
Agroforestry means some trees remain.
What are two benefits of trees in agroforestry?
- Provides shade
- Increases infiltration and interception
What is afforestation?
Tree planting, such as the Great Green Wall across the Sahel.
How do tree roots help in reversing desertification?
Roots help to bind the soil together reducing soil erosion.
What role does the canopy of trees play in soil preservation?
The canopy offers shade helping to prevent the soil from drying out.
What effect does tree planting have on soil nutrients?
Nutrients in the soil are replaced by falling leaves and branches.
How do trees affect animal and insect activity in the soil?
Trees increase animal and insect activity which helps improve soil quality.
What is the function of contour stones or bunds in reducing soil erosion?
They help to prevent the soil from being blown or washed away.
Fill in the blank: Contour stones or bunds help to _______ overland flow.
reduce
What is one way that contour stones or bunds contribute to soil health?
Ensuring that dead organic matter stays in one place and can decompose.
