Availability of Water Resources

Oceans account for 96.5 percent of the total amount of water on the planet, with freshwater accounting for only 2.5 percent. About 70% of this freshwater is preserved as glaciers and ice sheets in Antarctica, Greenland, and the world’s mountainous regions, with the other 30% maintained as groundwater in the world’s aquifers. In terms of the water availability of each person per year, India receives approximately 4% of global precipitation, thus ranking 133rd in the world. India’s entire renewable water resources are expected to be 1,897 sq km per year. Large sections of India are expected to join countries or regions with absolute water scarcity by 2025. So let’s discuss the availability of water on earth in detail. 

What is the Availability of Water? 

The amount of water used for human purposes without causing severe damage to ecosystems or even other users is referred to as water availability. Surface waters receive water from both runoffs and groundwater discharges. Groundwater, in turn, is reliant on surface water recharge.

Availability of Water on Earth

Water accounts for over 70% of the earth’s crust. It is an essential natural resource that You can find both above and below ground. The majority (about 97 percent) is seen as saltwater in the seas and oceans. This water is too salty to drink or use for irrigation. As a result, we only have availability to 3% of the total freshwater. 2.997 percent of this is covered in mountains or glaciers. So, for our water consumption needs, only around 0.003 percent of freshwater is widely available to us in the form of groundwater, river, lake, stream, soil moisture, and water vapour.

Sources of Water

The following are the different water sources:

• Rainwater: The primary source of water is rain. It is considered to be the purest form of natural water available. The rains also carry the smoke and dust particles into the atmosphere. As a result, the initial rain shower has a lot of pollutants.

• Oceans and seas: Oceans contain over 97 percent of the water on the planet. However, this water is too salty to drink, cultivate, or irrigate.

• River and lakes: Rainwater that falls on the earth’s surface is transmitted down the slope of the ground into rivers and streams. Water from melting glaciers on the mountains often falls into some rivers.

• Groundwater: A portion of the rain seeps through a layer of the earth when it rains. This water eventually reaches solid rocks and collects as groundwater. Drilling wells or sinking tube wells can also attain the water table and acquire groundwater.

Water Consumption

Water is required for the survival of all living species. On the other hand, humans rely on water more than plants and animals. We use water for a variety of uses in our daily activities, including:

• Domestic uses: Water is required for drinking, cleaning, cooking, including washing, among other things. Each individual in the house uses an average of 260 litres of water each day for various activities.

• Industrial uses: Water is used extensively in our industries at many phases of production, from using water as a raw material to the generation of energy. The usage differs per industry.

• Agriculture uses: For increased agricultural production, farmers rely heavily on the water in the form of rainfall. A lack of adequate rainfall and irrigation facilities significantly impact agricultural production. Farmers water their plants with a variety of irrigation systems.

• Water for recreation and transport: Water transportation is still used to transport oversized and bulky items such as machinery, coal, grain, and oil. The majority of recreational places are built beside lakes, rivers, and seas. Swimming, fishing, and sailing are among their favourite water activities.

Water Cycle

The water cycle is the movement of water from the earth’s surface to the atmosphere and returning to the planet. It is a cyclical process that keeps repeating itself. The following are the stages of the water cycle:

• Evaporation: 

When the sun heats water in rivers, lakes, or even the ocean, it converts it to vapour or steam. Water vapour escapes from rivers, lakes, and oceans and then into the atmosphere. The ocean, sea, lakes, and rivers provide around 90% evaporation. 

Plant transpiration is responsible for the remaining 10%. Water vapour is the gaseous form of water particles.

• Formation of a cloud: 

Warm air begins to cool as it rises. Because cool air did not hold as much water vapour as warm air, a few of the vapours condensed onto small dust particles in the air, forming tiny water droplets surrounding them. When these water droplets combine, they form a visible cloud.

• Condensation:

When water vapours enter the air, the temperature drops and the vapours condense back into liquid droplets, forming clouds. Condensation is the transformation of water vapour into liquid droplets.

• Precipitation: 

It occurs whenever clouds become saturated with water vapour and heavy with water, causing the water to fall back to earth as rain, hail, even snow.

Conclusion

On the earth’s surface, water flows between the atmosphere, ocean, rivers and streams, snowpacks and ice sheets, and the underground. For agriculture, human consumption, industry, and energy generation, water availability is crucial as both the groundwater and surface water. Surface water (lakes, rivers, and reservoirs) and groundwater are freshwater sources (found underground in rock or soil layers and accessed through wells or natural springs). Freshwater is continually travelling between the atmosphere, the ocean, and various freshwater sources.