Basic Science and Technology - Junior Secondary 3 - Environmental hazard V - Desertification

TERM: 1^ST TERM

WEEK: 8

CLASS: Junior Secondary School 3

AGE: 14 years

DURATION: 40 minutes each for 2 periods

DATE:

SUBJECT: Basic Science

TOPIC: Environmental hazard V - desertification

SPECIFIC OBJECTIVES: At the end of the lesson, the learners should be able to

1. ) Define desertification
2. ) Discuss the classification of deserts
3. ) Outline the geographical zones prone to desertification in Nigeria
4. ) Enumerate the human activities that lead to desertification
5. ) Outline the effects and control measures against desertification

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, story-telling, videos from source

INSTRUCTIONAL MATERIALS: Recommended Basic Science textbooks for Junior Secondary School 3

INSTRUCTIONAL PROCEDURES: PERIOD 1-2:

NOTE

ENVIRONMENTAL HAZARD V- DESERTIFICATION

Desertification is the process by which fertile land becomes desert-like as a result of various factors, including drought, deforestation, and inappropriate agricultural practices. It leads to the degradation of land in arid, semi-arid, and dry sub-humid areas, reducing productivity and biodiversity.

Classification of Deserts
Deserts are classified based on climate and physical characteristics:

• Hot Deserts: Found in subtropical regions, these deserts have high temperatures and little rainfall. Examples include the Sahara and Arabian Deserts.
• Cold Deserts: Located at high altitudes or in polar regions, these deserts experience low temperatures and minimal precipitation. Examples include the Gobi and Antarctic Deserts.
• Coastal Deserts: Situated along coastlines with cold ocean currents, these deserts are often cooler and experience fog. The Atacama Desert in South America is an example.

Geographical Zones Prone to Desertification in Nigeria
Desertification in Nigeria mainly affects the northern regions, where semi-arid and arid climates are prevalent. States prone to desertification include Sokoto, Katsina, Jigawa, Kano, Borno, Yobe, and parts of Bauchi, Gombe, and Zamfara.

Human Activities That Lead to Desertification
Several human actions contribute to desertification, such as:

• Overgrazing: Excessive grazing by livestock removes vegetation, exposing soil to erosion.
• Deforestation: Cutting down trees for fuel, construction, or agriculture reduces root systems that protect soil.
• Unsustainable Farming Practices: Poor agricultural practices, such as continuous cropping and improper irrigation, deplete soil nutrients and lead to erosion.
• Urbanization: Expanding urban areas can lead to soil sealing and reduce the availability of fertile land.

Effects and Control Measures Against Desertification

Effects:

Desertification results in reduced agricultural productivity, loss of biodiversity, water scarcity, and an increase in poverty and migration as communities lose viable land.

Control Measures:

• Afforestation and Reforestation: Planting trees helps bind the soil and prevents erosion.
• Sustainable Land Management: Techniques like crop rotation, contour farming, and controlled grazing help preserve soil health.
• Education and Awareness: Promoting awareness of sustainable practices can reduce harmful activities contributing to desertification.
• Government and Community Initiatives: Policies and community-led programs can work toward land restoration and soil conservation efforts.

EVALUATION:

1. What is desertification, and how does it affect arid and semi-arid regions?
2. Describe the different types of deserts and provide examples of each type.
3. Which regions in Nigeria are most prone to desertification, and why?
4. Identify and explain human activities that contribute to desertification in Nigeria.
5. What are some effective control measures to prevent or reduce desertification, and how do they work?

CLASSWORK: As in evaluation

CONCLUSION: The teacher marks their books and commends them positively