Basic Science and Technology
Week 5 and 6
Basic 5 / Primary 5
Previous lesson :
The pupils have previous knowledge of Land Pollution
Erosion . Changes Around Us
Behavioural objectives :
At the end of lesson, pupils should be able to:
- Define define erosion
- mention types of erosion
- say the causes of erosion
- mention ways by which erosion can be controlled .
Instructional Materials :
- Wall charts
- Related Online Video
- Flash Cards
- Some soil sample in Bucket.
Methods of Teaching :
- Class Discussion
- Group Discussion
- Asking Questions
- Role Modelling
- Role Delegation
Reference Materials :
- Scheme of Work
- Online Information
- 9 Year Basic Education Curriculum
What is Erosion ?
Erosion is the removal or washing away of soil nutrients by water , wind or human activities . These factors that are responsible for washing away soil nutrients are known as agents of erosion .
What are the types of Erosion ?
Rill Erosion : This occurs when rapid movement of water or strong wind removes the soil cover surface . This is done when a channel is form by the frequent movement of water through its channel thereby creation loss of soil nutrients
Gulley Erosion : This type of erosion is caused by a very deep violent movement of water which causes deep percolation of water . Gulley erosion causes deep holes in the soil .
Hill and Sheet Erosion : High hills are susceptible to hill and sheet erosion as water that moves rapidly downwards the slope of the hill washes away soil nutrients .
Wind Erosion : This is easily noticed in the arid region when strong wing blows away light upmost part of the soil particles and nutrients because of lack of rain or green vegetation .
What are the causes of Erosion ?
- Absence or inadequate rainfall
- too much rainfall
- human activities like deforestation
- rough or violent movement of water
- over grazing
- poorly constructed water dams, channels or irrigation
What are the effects of Erosion ?
- Soil nutrients are lost and harvest may not be bountiful
- Soil may become unfertile and less fruitful
- Erosion makes land surface unsafe and unmotorable for drivers
- Deep gulley make cause landslide
Ways by which erosion can be controlled
- Planting of cover crops
- Making or slopes , contours or ridges
- Planting of tress
- Avoid over grazing
- Avoid bush burning
- Encourage afforestation
The topic is presented step by step
The class teacher revises the previous topics
He introduces the new topic
The class teacher allows the pupils to give their own examples and he corrects them when the needs arise
The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.
The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.
He or she does the necessary corrections when and where the needs arise.
- What is erosion
- Mention two types of erosion
- Mention two agents of erosion
- Mention two effects of erosion
- Mention two ways of solving the problem of erosion
Prepare for the next lesson by reading about environment quality