Natural Environment
Lithosphere
The word lithosphere is derived from the Greek word lithos meaning rocky and sphaeros 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 on the ocean floor.
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
The origin of the word hydrosphere is from the Greek word hydro meaning water and sphaeros 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
- Rivers
- Lakes
- Seas and Oceans
Broadly there are two types of water bodies: fresh water bodies (rivers, lakes etc.) and saline water bodies (seas and oceans)
Hydrosphere is essential for all living organisms.
Atmosphere
The origin of the word atmosphere is from the Greek word Atmos meaning vapour and sphaeros meaning ball / globe. It is the thin layer of air that surrounds the earth. 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. The gravitational force of the earth holds the atmosphere around it.
The depletion of the ozone layer is a cause of serious concern for all of us.
Biosphere
Biosphere is also called the living world. Plant and animal kingdom together make the biosphere. It is a narrow zone of the earth where the land, water and air interact with each other to support life.
Ecosystem
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. There could be an ecosystem of the following:
| Rainforest | Grassland | Desert | Mountains |
| Lake | River | Ocean | Pond |