2.7. Water

Water is a vital renewable natural resource. Three-fourths of the earth’s surface is covered with water. It is therefore appropriately called the ‘water planet’.

Water is essential for life and covers much of our planet, which gives it the name 'water planet.' Almost 75% of the Earth's surface is water, emphasizing its importance in supporting life, ecosystems, and climate.

Think of Earth as a giant blue marble. Just like how a marble has its different parts—color, shine, and surface—Earth has its various parts, with water being one of its most important features.

Fresh water accounts for only about 2.7 per cent. Nearly 70 per cent of this occurs as ice sheets and glaciers in Antarctica, Greenland and mountain regions.

Freshwater is very limited, making up only a small fraction (about 2.7%) of the total water on Earth. A significant portion of this freshwater is locked in ice, making it inaccessible for immediate human use. Only a tiny percentage can actually be used for drinking, agriculture, and other needs.

Imagine a large swimming pool filled with water, but only a small cupful is clean and drinkable. This illustrates how much of the water on Earth is not readily available for human consumption.

Its abundance only seems to vary because it is in constant motion, cycling through the oceans, the air, the land and back again, through the processes of evaporation, precipitation and run-off.

The water cycle describes how water moves from one part of the Earth to another, continually cycling through different states: liquid, vapor, and ice. Water evaporates into the atmosphere, falls as rain, and then runs off into rivers and oceans, completing the cycle.

Imagine water as a performer in a play, constantly changing clothes: it starts as a liquid in the ocean, puts on its vapor 'costume' as it evaporates, falls as rain, and returns back to lakes and rivers to start the cycle all over again.

Humans use huge amounts of water not only for drinking and washing but also in the process of production. An average urban Indian uses about 150 litres of water every day.

Water is essential for various human activities, including personal use (like drinking and hygiene) and industrial uses (like agriculture and manufacturing). On average, a person uses a significant amount of water daily for various tasks.

Consider your daily routine: brushing your teeth, taking a shower, and cooking. Each of these activities uses water, adding up to around 150 liters daily, similar to filling several large buckets.

There is scarcity of water in many regions of the world. Most of Africa, West Asia, South Asia, parts of western USA, north-west Mexico, parts of South America and entire Australia are facing shortages in fresh water supply.

Many regions worldwide face significant water shortages due to a combination of inadequate rainfall and over-exploitation of water resources. Areas such as parts of Africa and Australia regularly experience drought, affecting both people and wildlife.

Think of a sponge: if you use it to soak up too much water without giving it a chance to dry out, it won’t be able to absorb water effectively. Similarly, overusing water sources leads to depletion.

Discharge of untreated or partially treated sewage, agricultural chemicals and industrial effluents in water bodies are major contaminants.

Water pollution occurs when harmful substances enter water bodies, making them unsafe for drinking and other uses. Common sources include untreated sewage and chemicals from agriculture and industries.

Imagine a beautiful lake filled with clear water, but then think about throwing in trash and chemicals. The lake would become dirty and unusable, much like how pollutants harm our water supply.

Water harvesting is another method to save surface runoff. Forest and other vegetation cover slow the surface runoff and replenish underground water.

Water conservation involves strategies to use water more efficiently and ensure more is available for future use. Techniques like water harvesting and maintaining vegetation help collect and conserve water.

Consider planting a garden: using rainwater to hydrate the plants instead of solely relying on a hose saves water. This practice can extend to larger scales, like cities utilizing rainwater systems.

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