Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 3rd Term
Week: 9
Age: 15 years
Duration: 45 minutes
Subject: Geography
Curriculum Theme: Geography
Previous Lesson: Stages of River Development: Lower cource, Deltas.
Topic: Action of Winds
Subject Matter: definition of wind action, wind erosion processes including abrasion attrition and deflation, wind erosion landforms including rock pedestal zeugens and yardangs, wind deposition features including loess barchans and seif dunes

Specific Objectives

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

Cognitive Domain:

Define wind action.
Describe the processes of wind erosion, including abrasion, attrition, and deflation.
Identify and describe wind erosion landforms such as rock pedestals, zeugens, and yardangs.
Identify and describe wind deposition features like loess, barchan dunes, and seif dunes.

Affective Domain:

Appreciate the importance of wind as a geomorphic agent in shaping the Earth’s surface.
Show interest in observing and understanding various landforms.

Psychomotor Domain:

Draw simple diagrams of wind erosion and deposition landforms.
Construct simple models illustrating wind-formed features.

Collaborate with peers to discuss and share knowledge about wind action.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Senior Secondary Schools.
State Unified Scheme of Work for Geography, SSS 1.
Okunrotifa, P.O. (2010). Senior Secondary Geography for Nigerian Schools. University Press Plc.
Adeleke, B.O. (2007). Essential Geography for Senior Secondary Schools. Tonad Publishers.

Instructional Materials

The teacher will teach this lesson with the aid of:

Pictures and slides showing wind erosion and deposition landforms.
Models of rock pedestals, barchans, and seif dunes.
Diagrams illustrating abrasion, attrition, and deflation.
Whiteboard or chalkboard and markers/chalk.

Rationale for the Lesson

Understanding the action of winds helps pupils to comprehend how natural forces modify the Earth’s surface, particularly in dry regions. This knowledge enables pupils to appreciate the diverse landscapes around them and the environmental processes that create them.

Prerequisite/Previous Knowledge

Pupils are assumed to have a basic understanding of weathering, erosion, and the concept of wind as a natural element from their previous lessons.

Lesson Content/Board Summary

Action of Winds

Definition of Wind Action

Wind action refers to the geological processes by which wind erodes, transports, and deposits materials on the Earth’s surface. It is most effective in dry, arid, or semi-arid regions with sparse vegetation.

Wind Erosion Processes

Wind erodes the land through different processes. These include:

Deflation: This is the lifting and removal of loose, dry, unconsolidated fine materials like dust and sand from the surface by strong winds. It creates deflation hollows.
Abrasion: This occurs when wind-blown sand particles hit and scour rock surfaces, wearing them down. It is like a natural sandblasting effect.
Attrition: This is the process where wind-blown particles (like sand grains) collide with each other during transport, causing them to break down into smaller, rounder fragments.

Wind Erosion Landforms

The continuous action of wind erosion creates distinct landforms. Some common wind erosion landforms are:

Rock Pedestal (Mushroom Rock): An isolated rock mass with a narrower base and a broader top, formed when wind abrasion is concentrated near the ground where sand particles are heavier and more abundant.
Zeugen: Table-like masses of soft rock capped by a more resistant layer, separated by furrows. Wind abrasion erodes the softer rock faster than the harder cap.
Yardang: Elongated, streamlined ridges of rock, often several meters high and kilometers long, carved by wind abrasion parallel to the prevailing wind direction.

Wind Deposition Features

When wind loses energy, it deposits the materials it has been carrying, leading to the formation of depositional landforms. These include:

Loess: Fine, yellowish, unconsolidated sediment, primarily silt, deposited by wind. It can form thick, fertile deposits over vast areas far from its source.
Barchan Dunes: Crescent-shaped sand dunes with horns pointing downwind, typically found in areas with a limited sand supply and a relatively constant wind direction.
Seif Dunes (Longitudinal Dunes): Long, parallel ridges of sand, oriented parallel to the prevailing wind direction, formed in areas with abundant sand and strong, consistent winds.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils, checks attendance, and asks pupils about their observations of wind effects in their environment, such as dust movement or sand accumulation. The teacher then introduces the topic “Action of Winds” and explains that they will learn how wind shapes the Earth’s surface.
Pupils’ Activity: Pupils respond to greetings, answer questions, and listen attentively to the introduction.
Learning Point: Pupils are introduced to the topic and relate wind action to their daily experiences.

Step 2: Definition of Wind Action and Erosion Processes

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher defines wind action and explains the three main processes of wind erosion (deflation, abrasion, attrition) using diagrams and simple analogies. The teacher asks questions to ensure understanding.
Pupils’ Activity: Pupils listen, take notes, ask questions for clarification, and answer questions posed by the teacher.
Learning Point: Pupils define wind action and describe the processes of deflation, abrasion, and attrition.

Step 3: Wind Erosion Landforms

Time: 10 minutes
Teaching Skill: Illustration/Description
Teacher’s Activity: The teacher displays pictures and models of wind erosion landforms (rock pedestals, zeugens, yardangs). The teacher describes how each landform is created by wind erosion and highlights their distinguishing features.
Pupils’ Activity: Pupils observe the pictures and models, listen to the explanations, and make simple sketches in their notebooks.
Learning Point: Pupils identify and describe various wind erosion landforms.

Step 4: Wind Deposition Features

Time: 10 minutes
Teaching Skill: Explanation/Visualisation
Teacher’s Activity: The teacher explains how wind deposits materials when its energy decreases, leading to depositional features. The teacher describes loess, barchan dunes, and seif dunes, using diagrams and models to illustrate their shapes and formation.
Pupils’ Activity: Pupils pay attention, take notes, and discuss the characteristics of each depositional feature.
Learning Point: Pupils identify and describe wind deposition features.

Step 5: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define wind action.
Mention two processes of wind erosion.
List three landforms created by wind erosion.
Describe a barchan dune.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarisation/Reinforcement
Teacher’s Activity: The teacher summarises the key points of the lesson, reiterating the definition of wind action, its erosion processes, and the resulting erosion and deposition landforms. The teacher assigns homework for pupils to draw and label one wind erosion landform and one wind deposition feature.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their learning and are encouraged to practice drawing the landforms.

Lesson Keywords

Wind Action – The geological processes of erosion, transportation, and deposition by wind.
Deflation – The removal of loose, fine material by wind.
Abrasion – The wearing down of rock surfaces by wind-blown particles.
Attrition – The breaking down of wind-blown particles by collision with each other.
Rock Pedestal – A mushroom-shaped rock formed by differential wind abrasion.
Zeugen – Table-like rock masses with hard caps formed by wind erosion.
Yardang – Elongated, streamlined ridges of rock carved by wind abrasion.
Loess – Fine, wind-deposited silt.
Barchan Dune – A crescent-shaped sand dune.
Seif Dune – A long, longitudinal sand dune.

Differentiation

For pupils who grasp concepts quickly, the teacher can encourage them to research other less common wind-formed features. For pupils needing more support, the teacher will provide simplified diagrams and allow more time for hands-on model manipulation and peer-assisted learning.

Note for teachers using this lesson plan

Teachers should ensure that visual aids are clear and relevant to the Nigerian context where possible. Encourage pupils to relate the concepts to any local observations of wind effects. Emphasise safety if conducting any outdoor observations related to wind.