[Geography Notes] on What is Water? Pdf for Exam

Water is one of the most important things required for life and our planet Earth is the only planet which is having liquid water. Can you imagine your life without water? Absolutely not. If someone asks you what is water? Then probably your answer will be H2O. As per the Cambridge dictionary, water means a clear liquid, without colour or taste, that falls from the sky as rain and is necessary for animal and plant life. Water does not have a colour of its own or does not have any shape.

Here, we will be discussing the water, its various sources, and terms related to it such as surface water, groundwater, what is a sea, what are ocean waves, sea waves definition, tides and waves, different types of ocean waves, etc.

Sources of Water

There are various sources of water which are mentioned below:

Surface Water: 

Surface water is the most common source of water and they provide maximum water for drinking and essential purposes. They are easily accessible in most of the regions. Mostly the water of this source is freshwater which fulfils the needs of human beings at large.

Surface water includes the following:

• Rivers

• Lakes

• Streams

• Reservoirs

• Wetlands

Groundwater  

There is a large source of water under our feet and this water not only helps the plants to grow but useful for human beings as well. Wells, handpumps, tubewells, etc. are used to extract the groundwater or sometimes this groundwater comes naturally on the surface then it is called a spring.

Stormwater

It is also known as runoff or rainwater. This water we get because of the change in weather or heavy weather. For example, rain, snow, hail, etc. This water is fresh but actually got polluted in the process of coming down the earth and needs filtration.

Saltwater 

Our planet is made up of 70% ocean water but this water is salt water and it is very difficult to use it for human purposes and thus we depend on freshwater to survive. We are trying to use ocean water with new and modern technology which helps in removing the salt content in water to make it useful.

Icecap Water

Glaciers and Polar Ice Caps are a great source of fresh water and this freshwater floats into the ocean sometimes and sometimes with the help of rivers becomes accessible to the people but the presence of these glaciers and polar icecaps is very necessary to maintain the earth’s temperature.

Let’s Study Other Terms Related to Water:

What is the Sea?

A water body that consists of saltwater and can be a part of the ocean or can be surrounded by land as well. For example the Mediterranean sea, Arabian Sea, Black Sea, etc.

What are Sea Waves?

The movement of the water up and down on the surface because of the oceanic movements under the water are called sea waves. It is a type of ocean wave. The work of sea waves can be observed in the diagram, the lower bend is called a wave trough whereas the upper bend is called a wave crest. There are various types of sea waves such as breaking waves, shallow water waves, deep water waves, spilling waves, plunging waves, collapsing waves, surging waves, onshore waves, tidal waves, etc. 

What is a Tide?

These are short or long-period sea waves that are formed in the ocean due to the gravitational pull of the sun and the moon. There are various types of tides that are formed in the oceans. There are three types of tides according to the frequency ie. Semi-Diurnal Tides, Diurnal Tides and  Mixed whereas there are two types on the basis of the position of the Earth, the Sun, and the Moon i.e. Spring Tides and Neap Tides.

Ocean Tides or Currents

The continuous movement of water from one region to another in the ocean is called ocean tides. A number of factors play an important role in this movement such as breaking waves, winds, Coriolis force, temperature, and salinity, etc. They are also called currents such as warm currents and cold currents. Here in the diagram, red arrows represent the warm currents and blue arrows represent the cold currents. The canary current, the labrador, the Benguela, etc. are examples of cold currents whereas the Gulf stream and North Atlantic drift are examples of warm currents.

Distribution of Water

The planet Earth is the only planet with the presence of liquid water and it is covered with almost 71% of water and most of the earth’s water is in oceans which covers almost 97% of the Earth’s water which is saltwater and the rest of the water i.e. 3% is freshwater which is present in other forms like glaciers, polar ice caps, rivers, lakes, streams, etc.