CBSE Class 7 Geography – 1. Environment (Notes)

Environment – Place, people, things and the nature that surround us are called the environment.

The word environment has its roots in the French word Environer / Environner which means neighbourhood.

Environment is our basic life support system.

Our environment is constantly changing because of our needs.

Human beings are modifying or destroying the natural environment.

The air is polluted by car fumes, water is collected in a pot, food is served in utensils and land is used for building houses and factories.

Human beings are the ones who make cars, factories, houses, vessels, pots etc.

There by modifying the environment.

Biotic components – A living component of an ecosystem such as plants and animals are called biotic component. Examples – plants, animal etc.

Abiotic components – The non – living elements such as land, air and water are called a biotic component. Ex – Water, light, wind, soil, humidity, minerals, gases.      

Components of the environment:

Natural environment

Human made environment

Human environment

Natural Environment – Environment that consist living and non living things (meaning in this case not artificial and human) is called natural environment. Ex. land, water, air etc.

The natural environment consists of the following:

Land

Water

Air

Plants and Animals

Lithosphere – The rigid outer part of the earth, consisting of the crust and upper mantle is called lithosphere.

The word lithosphere is derived from the Greek word ‘lithos’ meaning ‘rocky’ and ‘phere’ meaning sphere.

It is the solid crust or the hard top layer of the earth.

It comprises of: rocks and minerals.

It has various landforms such as mountains, plateaus, plains, valleys, etc.

These landforms are found both over the continents and also on the ocean floors.

Features of lithosphere:

It is covered by a thin layer of soil.

It is an irregular surface.

It is a source of mineral wealth

 Uses of Lithosphere

Lithosphere or land is used for agriculture, grazing of animals and human settlement.

The land that we see around us is used for building factories, roads, parks, houses, museums etc.

Hydrosphere – All the water on the earth’s surface, such as lakes and seas, and sometimes including water over the earth’s surface are called hydrosphere.

The origin of the word hydrosphere is from the Greek word ‘hydro’ meaning water and ‘sphere’ meaning sphere.

 The domain of water is called the hydrosphere.

It consists of various sources of water and different types of water bodies which include river, lakes, Sea and oceans etc.

There are two types of water bodies: fresh water bodies (rivers, lakes etc.) and saline water bodies (seas and oceans)

Atmosphere – The thin layer of air that surrounds the earth is called atmosphere.

The origin of the word ‘atmosphere’ is from the Greek word ‘Atmos’ means vapour and ‘sphere’ meaning ball / globe.

The following are the features of atmosphere:

It consists of a number of gases, dust and water vapour.

It protects us from the harmful rays and the scorching heat of the sun.

The changes in the weather and climate are caused by the changes in the atmosphere.

Biosphere (living world) – The narrow zone of the earth where land, water, and air interact with each other to support life is called biosphere.

Plant and animal kingdom together make the biosphere.

Ecosystem – A community or group of living organisms that live in and interact with each other in a specific environment is called eco system.

All plants, animals and human beings depend on their immediate surroundings. They are often interdependent.

There is a relationship among living beings and between living beings and non-living things. This relationship makes the ecosystem.

In other words, it is the system formed by the interaction of all living organisms with each other and with the physical and chemical factors of the environment in which they live, all linked by the transfer of energy and material.

               

 

                

Human made component – The surroundings that provide facilities for human needs is called human made environment.

The human made component of the environment are the creations by human beings which include bridges, roads, dams, parks and monument etc.

The human environment consists of the individual and his interactions which include the following:

Family, Community, Religion, Educational , Economic and political situations

Human Environment – The surroundings made by man is called human environment.

The interaction between human beings and environment is a continuous process.

The early humans tried to adapt to the environment.

The following are the examples of uses / changes made in the environment by human beings:

Growing crops

Domesticating Animals

Leading a Settled Life

Some of the significant changes which helped in progress of human life are:

Invention of wheel, surplus food production, barters system, trade and commerce, etc.

The Industrial Revolution helped in large scale production of goods.

 In modern times, the information technology has made long distance communication easier and faster across the globe.

June 5 every year is celebrated as the World Environment Day.

Barter System – A trade in which goods are exchanged without the use of money is called barter system.