WATER AND THE BLUE PLANET
1.1 Introduction Of “The Blue Planet” (The Earth)
71% of the earth is covered by water.
29% of the surface is covered by land.
It is the only known planet with life.
Fig1.1 the blue planet
The earth is known as “Blue Planet” occupies a special place in the solar system. The earth consists of three spheres. They are known as Atmosphere, the Hydrosphere and the Lithosphere. The interrelationship that exists among these three spheres is the foundation of the Biosphere. Atmosphere
Fig1.2 Components of the biosphere)
1.2. Special features of these different spheres
1. Atmosphere: It is composed of various gases and water particulars. 2. Hydrosphere: 71% of the earth’s surface is covered by water.
It consists of oceans, seas, lakes, rivers and streams. 3. Lithosphere: It is the surface layer of the earth.
4. Biosphere: There is a biodiversity which consists of numerous eco-systems.
The earth covered by water can be termed as Hydrosphere. The water over the earth’s surface changes into solid, liquid or gas forms alternatively. The distribution of water over the surface of the earth is shown below. Vapour 0.001%
Saline lakes and
Fig1.3 Global distribution of water
Source: Educational publications Department
1.4. What is water?
Water consists of two hydrogen atoms and one oxygen atom. This is concerned as a compound that cannot be made easily. Absolutely pure water cannot be found in nature. Depending upon the impurities, it has to be subjected to various treatments.
1.5. Global water
Another noteworthy feature is that more than 97% of Global water is trapped in the oceans. Major portion of what is left is in the frozen state and not available for human use. When we examine the following figure, we can realize that only a very small proportion of water on the surface of the earth can be used by man.
Interior seas Sea