Environmental Hazard III (Lesson note)

Detailed Lesson Note

Subject: Basic Science
Class: JSS 3 (Grade 9)
Topic: Environmental Hazard 3
Duration: 40 minutes

Week: Two
Date: To be inserted by the teacher
Average Age: 13–14 years
Sex: Mixed
Instructional Materials:

• Map of Nigeria/Africa showing desert-prone areas
• Charts showing desertification effects
• Diagram of ozone layer and depletion process
• Pictures of CFC products (spray cans, refrigerator, AC)

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Lesson Objectives

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

1. Define desertification correctly. (Knowledge – Lower Domain)
2. Identify and describe geographical areas in Nigeria and Africa prone to desertification. (Comprehension/Application – Middle Domain)
3. Analyze at least three causes of desertification and suggest two control measures. (Analysis – Higher Domain)
4. Evaluate the causes of ozone layer depletion. (Evaluation – Higher Domain)
5. Discuss the effects of ozone layer depletion on man and the environment, and propose two control measures. (Synthesis – Higher Domain)

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Lesson Presentation (40 minutes)

Steps	Teacher’s Activities	Learners’ Activities	Evaluation	Time
Introduction	Greets students and recalls last topic (Environmental Hazard 2 – erosion/flooding). Asks: “Have you heard of desertification or ozone layer before?”	Students respond with prior knowledge.	Mention one environmental hazard studied last week.	5 mins
Step 1: Desertification – Meaning	Defines desertification: the process by which fertile land becomes desert, typically due to drought, deforestation, or poor farming practices.	Students repeat the definition and give examples.	What is desertification?	5 mins
Step 2: Geographical Areas Affected	Uses a map of Nigeria/Africa to explain areas prone to desertification:

• Nigeria: Sokoto, Borno, Yobe, Katsina, Kano.
• Africa: Sahel region (Niger, Chad, Sudan, Mali). | Students point out affected areas on map/chart. | Mention two states in Nigeria affected by desertification. | 6 mins |
  | Step 3: Causes & Control of Desertification | Explains causes:
• Overgrazing
• Deforestation
• Over-cultivation
• Climate change/drought
  Control measures:
• Afforestation/planting trees
• Irrigation farming
• Controlled grazing
• Use of improved farming practices | Students brainstorm additional causes and suggest solutions for their communities. | State one cause and one control measure of desertification. | 8 mins |
  | Step 4: Ozone Layer Depletion – Causes | Explains that the ozone layer protects the Earth from harmful UV rays. Causes of depletion include:
• Release of CFCs (chlorofluorocarbons from sprays, fridges, ACs)
• Industrial gases
• Deforestation | Students mention common products that release CFCs. | Mention one cause of ozone layer depletion. | 6 mins |
  | Step 5: Ozone Layer Depletion – Effects & Control | Explains effects:
• Skin cancer and cataracts
• Global warming and climate change
• Poor crop yield
• Death of aquatic life
  Control measures:
• Ban CFC products
• Encourage use of eco-friendly appliances
• Plant more trees | Students discuss in groups and share solutions for ozone depletion in Nigeria. | Mention one effect and one control measure of ozone layer depletion. | 8 mins |
  | Conclusion | Reviews:
• Desertification (meaning, areas, causes, control)
• Ozone layer depletion (causes, effects, control) | Students answer oral revision questions. | List two hazards discussed today. | 2 mins |

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Evaluation Questions

1. Define desertification.
2. Mention two geographical areas affected by desertification.
3. State two causes and one control measure of desertification.
4. List two causes of ozone layer depletion.
5. Mention one effect of ozone layer depletion on man and one control measure.

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Assignment

1. Write five causes of desertification and their corresponding control measures.
2. Explain three effects of ozone layer depletion on man and the environment.