- The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene is a minimum of 50 litres per person per day. This amount is about two and a half buckets of water per person per day.
- Water shortage has become a matter of concern throughout the world. It is estimated that in a few years from now more than one third of the people in the world could face water scarcity.
- 71% of the earth’s surface is covered with water. Almost all the water on the earth is contained in the seas and oceans, rivers, lakes, ice caps, as groundwater and in the atmosphere. However, most of this water is not fit for human consumption. The water that is fit for use is freshwater.
- When water circulates through the water cycle it can be found in all the three forms, i.e., solid, liquid and gas.
- The solid form, snow and ice, is present as ice caps at the poles of the earth, snow-covered mountains and glaciers. Liquid water is present in oceans, lakes, rivers, and even underground. The gaseous form is the water vapour present in the air around us. The continuous cycling of water among its three forms keeps the total amount of water on the earth constant even when the whole world is using it.
- In a layer below the ground surface, all the space between particles of soil and gaps between rocks are filled with water. The upper limit of this layer is called the water table. The water table varies from place to place, and it may even change at a given place. The water table may be at a depth of less than a metre or may be several metres below the ground. The water found below the water table is called groundwater.
- The rainwater and water from other sources such as rivers and ponds seeps through the soil and fills the empty spaces and cracks deep below the ground. The process of seeping of water into the ground is called infiltration. The groundwater thus gets recharged by this process. At places the groundwater is stored between layers of hard rock below the water table. This is known as an aquifer. Water in the aquifers can be usually pumped out with the help of tube wells or hand pumps.
- Water drawn from under the ground gets replenished by seepage of rainwater. The water table does not get affected as long as we draw as much water as is replenished by natural processes. However, water table may go down if the water is not sufficiently replenished. This may happen due to many reasons. Increase in population, industrial and agricultural activities are some common factors affecting water table. Scanty rainfall is another factor that may deplete the water table. Yet another factor affecting water table could be deforestation and decrease in the effective area for seepage of water.
- Increasing population creates demand for construction of houses, shops, offices, roads and pavements. This decreases the open areas like parks, and playgrounds. This, in turn, decreases the seepage of rainwater into the ground.
- Water is used by all the industries. Almost everything that we use needs water somewhere in its production process. The number of industries is increasing continuously. Water used by most of the industries is drawn from the ground.
- A majority of farmers in India depend upon rains for irrigating their crops. Irrigation systems such as canals are there only in a few places. Even these systems may suffer from lack of water due to erratic rainfall. Therefore, farmers have to use groundwater for irrigation. Population pressure on agriculture forces increasing use of groundwater day by day. This results in depletion of water table.
- The distribution of water over the globe is quite uneven due to a number of factors. Some places have good amount of rain and are water-rich. On the other hand, there are deserts which have scanty rainfall.
- The rainwater can be used to recharge the groundwater. This is referred to as water harvesting water harvesting or rainwater harvesting.
- A farmer using water in the field can also use water economically. Drip irrigation is a technique of watering plants by making use of narrow tubings which deliver water directly at the base of the plant.
- Water-wise habits
- Turn off taps while brushing
- Mop the floor instead of washing
- We need to be worried about the wastage during the supply of water through pipes, the leaking taps in buildings and other places. Unnecessary use of water and overdrawing from groundwater should be avoided. Recharge of water to the ground should be increased.
- The need of the hour is that every individual uses water economically. Plants wilt and ultimately dry-up if they are not watered for a few days.
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