Lesson Notes By Weeks and Term - Senior Secondary School 2

SUBJECT: GEOGRAPHY

CLASS:  SS2

DATE:

TERM: 1ST TERM

REFERENCE MATERIAL

• Essential Geography for Senior Secondary Schools, O.A. Iwena.

 
WEEK SEVEN

TOPIC: CLASSIFICATION OF CLIMATE

Climate varies from place to place and the following are the common classification of climate:

1. Greek system of classification and 
2. Koppen system of classification

GREEK SYSTEM OF CLASSIFICATION OF CLIMATE

This is one of the earliest climatic classification which was made by the Greeks. The basis for the Greek classification is temperature. This system of classification divides the world into three climatic zones. These zones are:

1. Torrid zone: This zone is found within the tropics. It is very hot and has high 

    temperature throughout the year.

1. Temperate zone: It is found between the torrid and frigid zone and has moderate 

    temperature.

1. Frigid zone: It is found around the polar regions and It is very cold with low temperature 

    all year round. It has lot of ice-caps in most part of the year.

KOPPEN SYSTEM CLASSIFICATION OF CLIMATE

Thebasis for Koppen’s classification of climate aretemperature and rainfall. He identified five major climatic groups which correspond with the five principal vegetationgroups. These climatic groups are represented with capital letters as follows:

A-Tropical Rainy Climate

“ENVIRONMENTAL INTERVENTION”

Environment is defined as the total surrounding or medium of any organism in a given area.  This include the physical surroundings, climatic factors and other living organisms in that surrounding.

SPHERES OF THE ENVIRONMENT

The earth as an environment is grouped into four spheres:

1. Lithosphere: The solid portion of the environment which contains rocks, sand, soil, minerals etc.
2. Hydrosphere: This is the liquid portion of the environment like rivers, lakes and oceans.

iii.    Atmosphere: This is the gaseous portion of the environment where gases like oxygen, nitrogen, carbon-dioxide, ozone are found.

1. Biosphere: This is the portion of the environment where plants and animals are found.  These four spheres of the environment are interrelated and interdependent on each other.

Ecosystem: An ecosystem is defined as the community of plants and animals living together in harmony and interacting with their physical environment.

In other word; ecosystem can be defined as the relationship that exists between living thing and their non-living environment.

Components of Ecosystem

The ecosystem is made up of two main components.  These are:

(a)    Abiotic (non-living) component: These are the components like soil, water, gases, sunlight etc in the environment.

(b)    Biotic component: This is the living component of the ecosystem.  It includes plants and animals.

Biotic component can be grouped into three (3)

(1)    Autotrophs: This are also called the producers.  They include the green plants which manufacture their own food through a process known as photosynthesis.

(2)    Heterotrophs: These are called primary and secondary consumers.  These organisms cannot manufacture their own food but depend directly or indirectly on plants for their own food e.g. man, parasites, saprophytes.

(3)    Decomposers: These are micro – organisms that decompose dead organic matter in order to release nutrients required by producers to prepare their food e.g. Fungi and bacteria wholistically, the components of an ecosystem can be grouped into the following:

(1) Land (soil)        (2) Water (Lake, Oceans)    (3) plants        (4)  Animals

(5) Drainage (river)    (6)Climate (Atmosphere)

INTERDEPENDENCE WITHIN THE ECOSYSTEM

Interdependence is the word used to describe the relationship between the components of the ecosystem.  This is because, components in an ecostystem depend on one another and they cannot exist in isolation.  A state of inter-dependence within the ecosystem is best achieved where the components are undisturbed.

Inter-dependence in an ecosystem exists in three ways:

(1)    Interdependence within Abiotic components e.g. The weathering of rock to form soil or the evaporation of water to form cloud etc.

(2)    Interdependence within Abiotic components e.g. Animals depend on plants for food or the exchange of oxygen and carbondioxide by plants and animals.

(3)    Interdependence between the biotic and abiotic components e.g. plants depend on soil for support and nutrients, Autotrophs conver sunlight, energy.  Water and carbon dioxide during photosynthesis to produce food etc.

Environmental balance

Environmental balance refers to the ways of recycling matter and the flow of energy withing an ecosystem in order to ensure continuous supply or availability.

Environmental balance is achieved through the following processes:

(i)    Hydrological (water) cycle

(ii)    Carbon cycle

(iii)    Nitrogen cycle

(iv)    Mineral nutrient cycle

(v)    Food chain and food web. (for details, see pages  115 – 118 of Essential Geography)

EVALUATIONQUESTIONS

1. What is the Word ‘Interdependence’ mean?
2. What is Environmental balance and how is it achieved?

WEEKEND ASSIGNMENT

1. The liquid portion of the earth is called ________

    (a) Hydrosphere        (b) Biosphere    (c) Atmosphere

2. Animals, man and parasites are grouped as ______

    (a) Decomposers    (b) Heterotrophs    (c) Autotrophs

3. The relationship between organisms and its physical environment is called __________

    (a) Environment    (b) Ecosystem        (c) Community

4. The best example of autorophsare ________

    (a) Animals         (b) Man       (c) plants

5. One of these is not a way an environmental balance is achieved:

    (a) Food chain      (b) Water cycle    (c) Sand cycle

THEORY

1. What is an Ecosystem?
2. Mention the components of Ecocystem and briefly explain each of them.

INTERVENTIONS WITHIN THE NATURAL ENVIRONMENT

MEANING: Environmental intervention refers to the forces of nature and the activities of man that change the natural existence of the components of the eco-system. 

TYPES OF ENVIRONMENTAL INTERVENTION 

There are two types of interventions in our environmental.  There are man-made and natural intervention.

1. Natural Intervention includes Desert Encroachment, volcanism, sea - level changes, Earthquakes, climatic changes, Drought, flooding, Hurricane etc.
2. Human Interventions deal with man’s interference with the ecosystem through his activities.  Human intervention include:Deforestation, pollution, land reclamation, farming activities, construction urbanization, grazing, industrialization etc.

EVALUATION

1. What is Environmental Intervention.
2. Name the two types of Environmental intervention and give two examples of each.