Environmental Hazard V: Desertification

Subject: Basic Science

Class: JSS 3

Term: First Term

Week: 9

Age: 12 – 14 years

Topic: Environmental Hazard – Desertification

Sub-Topic: Causes, Effects, and Control Measures of Desertification

Duration: 40 minutes

Behavioural Objectives

By the end of the lesson, students should be able to:

1. Define desertification and explain its effects.
2. Identify geographical zones prone to desertification in Nigeria and beyond.
3. List the causes of desertification, including human activities like overgrazing and deforestation.
4. Propose control measures to prevent desertification.

Keywords

• Desertification: The process where fertile land becomes desert.
• Overgrazing: When animals feed too heavily on vegetation, degrading the land.
• Arid Regions: Areas with very low rainfall.
• Afforestation: Planting trees to reclaim desert areas.
• Drought: A prolonged period without rainfall.

Set Induction

The teacher asks:

• “Have you ever seen dry land where plants could no longer grow? What do you think caused it?”
  This prompts students to reflect on the factors that lead to land degradation and desert formation.

Entry Behaviour

Students may have heard about desertification from news reports, geography lessons, or experiences with dry farmlands.

Learning Resources and Materials

• Diagrams of desert-prone areas in Nigeria.
• Maps showing global desertification hotspots.
• Videos highlighting the impact of desertification on communities.

Building Background/Connection to Prior Knowledge

The teacher links the lesson to previous topics on environmental hazards, such as deforestation and bush burning, explaining how these practices accelerate desertification.

Embedded Core Skills

• Environmental Awareness: Understanding the causes and effects of desertification.
• Critical Thinking: Evaluating control strategies.
• Problem Solving: Developing solutions for affected areas.

Instructional Materials

• Basic Science textbooks
• Lagos State Scheme of Work
• Posters illustrating desert landscapes

Content

1. Definition of Desertification

Desertification is the process by which fertile land becomes desert-like, typically as a result of drought, deforestation, or poor agricultural practices.

2. Geographical Zones Prone to Desertification

1. Northern Nigeria – Sokoto, Borno, Yobe, Katsina, and Bauchi States.
2. Sahel Region of Africa – Countries bordering the Sahara desert.
3. Arid and Semi-Arid Zones – Areas with limited rainfall that are vulnerable to desert expansion.

3. Causes of Desertification

1. Overgrazing: Livestock eat away all vegetation, leaving the soil exposed.
2. Bush Burning: Burning vegetation destroys the protective cover of the soil.
3. Deforestation: Cutting down trees removes roots that hold the soil together.
4. Poor Irrigation Practices: Excessive water use can lead to soil salinization.
5. Climate Change: Rising temperatures and changing rainfall patterns worsen desertification.

4. Effects of Desertification

1. Loss of Farmland: Crops can no longer grow, reducing food supply.
2. Migration: People move away from degraded areas to find better living conditions.
3. Increased Poverty: Loss of agricultural productivity affects livelihoods.
4. Dust Storms: Bare soil is easily blown by wind, causing environmental hazards.
5. Water Scarcity: Reduced vegetation limits groundwater recharge.

5. Control Measures

1. Afforestation: Planting trees to restore vegetation.
2. Controlled Grazing: Limiting the number of animals in an area to prevent overgrazing.
3. Water Conservation: Using efficient irrigation methods to prevent soil salinization.
4. Soil Erosion Control: Building terraces or planting cover crops to protect soil.
5. Environmental Education: Teaching communities about sustainable land management.

Board Summary

• Desertification: Land degradation turning fertile land into desert.
• Causes: Overgrazing, deforestation, bush burning, poor irrigation.
• Effects: Loss of farmland, migration, poverty, dust storms.
• Control Measures: Afforestation, controlled grazing, water conservation.

Class Activity Discussion (FAQs)

1. What is desertification?
   • It is the process of land becoming desert-like and unable to support plants.
2. Where does desertification occur in Nigeria?
   • Northern states like Sokoto, Yobe, and Borno.
3. What causes desertification?
   • Overgrazing, deforestation, and poor irrigation.
4. How does climate change affect desertification?
   • Higher temperatures and less rain worsen the problem.
5. What is afforestation?
   • Planting trees to prevent desertification.
6. What are the effects of desertification?
   • Loss of farmland, poverty, migration, and dust storms.
7. How does overgrazing contribute to desertification?
   • Animals eat all the plants, leaving the soil bare and exposed.
8. What is soil salinization?
   • A buildup of salts in the soil, making it infertile.
9. Why is bush burning harmful?
   • It destroys vegetation, exposing the soil to erosion.
10. How can we prevent desertification?

• By planting trees, conserving water, and controlling grazing.

Teacher’s Activities

1. Show maps of desert-prone areas in Nigeria.
2. Explain how human activities lead to desertification.
3. Engage students in brainstorming solutions to control desertification.

Learners’ Activities

1. Discuss the effects of desertification on their communities.
2. Work in groups to propose strategies for combating desertification.
3. Complete worksheets on causes and control measures of desertification.

Evaluation: 15 Fill-in-the-Blank Questions

1. __________ is the process where fertile land becomes desert.
   a) Desertification
   b) Erosion
   c) Reforestation
   d) Conservation
2. Northern Nigeria is prone to __________.
   a) desertification
   b) urbanization
   c) afforestation
   d) flooding
3. __________ occurs when animals graze too heavily on vegetation.
   a) Overgrazing
   b) Irrigation
   c) Reforestation
   d) Salinization
4. Bush burning destroys __________ that protect the soil.
   a) vegetation
   b) minerals
   c) rocks
   d) rivers
5. __________ is the planting of trees to prevent desertification.
   a) Afforestation
   b) Deforestation
   c) Irrigation
   d) Erosion
6. __________ is caused by poor irrigation practices that leave salts in the soil.
   a) Salinization
   b) Overgrazing
   c) Reforestation
   d) Desertification
7. Desertification leads to __________, where people leave affected areas.
   a) migration
   b) afforestation
   c) erosion
   d) flooding
8. __________ helps protect soil from erosion by holding it together.
   a) Vegetation
   b) Plastic
   c) Sand
   d) Gravel
9. A common effect of desertification is __________ storms.
   a) dust
   b) snow
   c) rain
   d) hail
10. Communities can prevent desertification by conserving __________.
    a) water
    b) plastic
    c) paper
    d) salt

Conclusion

The teacher wraps up the lesson by emphasizing the importance of preventing desertification through sustainable land management practices. Students receive feedback on their answers and are encouraged to spread awareness about protecting the environment.