Types & Components of Environment// Unit 1// Environmental Education// TNTEU B.Ed

 

è TYPES OF ENVIRONMENT AND ITS COMPONENTS:

There are two kinds of environment –

                                    i.          Natural Environment

                                 ii.          Man- made Environment

Natural Environment:

All components that come into existence naturally are included in Natural Environment. The landforms on the Earth, the climate, soils, minerals, sunlight etc are components of our natural environment.

§  Natural Environment is classified into

  Biotic or living component

  Abiotic or physical component

     Components of biotic environment:

     Biotic component of environment are further classified as

  Aquatic – those living in water

  Terrestrial – those living on land

  Flora – consists of different species of vegetations like plants, grass, bushes, forests

  Fauna – consists of mammals and other species like birds, reptiles, fishes, sharks, whales, etc

  Others – consists of microorganisms like bacteria, viruses, fungus, etc.

     Components of Abiotic environment:

     Abiotic or Physical environment has three components     namely Lithosphere, Hydrosphere, Atmosphere.

     Lithosphere:

It refers to the crest of the Earth, constituted by rigid rocks    and soil.

Hydrosphere:

Consist of oceans, seas, rivers, streams, lakes, polar ice– caps, glaciers, groundwater, etc

Atmosphere:

Atmosphere is a gaseous envelope extending to a height of 20,000 kilometres from Earth’s surface. It consists of nitrogen, oxygen, carbon dioxide, hydrogen, argan, etc There are five layers in the atmosphere.

 



§ Troposphere: It extends to about 20 km from the surface and forms about 80% of the atmosphere. It comprises water vapor, ash, and dust particles. Thus, all climatic changes and weather systems exist in this layer. All hot air balloons and passenger planes exist within this layer.

§ Stratosphere: This layer extends from the end of the troposphere up to 30 km. It contains the ozone layer that is responsible for absorbing the harmful UV rays of the sun and preventing fatal conditions like skin cancer.

§ Mesosphere: The mesosphere extends 40 km beyond the stratosphere. The coldest temperature (-90 ) in the atmosphere is near the top of this layer. This is the layer that protects us against the meteors coming from space. They burn up in this layer and create shooting stars.

§ Thermosphere: This layer extends to approximately 300 km beyond the point where the mesosphere ends. It records some of the highest temperatures in the atmosphere (approximately 2000). Various satellites and the International Space Station are situated in this layer. This layer is also called the ionosphere.

§ Exosphere: The outermost layer of the atmosphere is called the exosphere which extends beyond 700 km. Thus, it serves as a boundary between the atmosphere of the Earth and outer space.

ª     Man - Made Environment:

An environment that has been created by humans to satisfy their requirements is said to be an “Man – Made Environment”. Humans have shaped their environments by constructing things like buildings, roads, dams and bridges, nuclear, hydroelectric and thermal power stations … with the help of advancement in science and technology. This involves social, cultural and institutional components.

 


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