Water : A Precious Resource
Introduction
- Water, the precious resource of the earth is useful to all living organism for maintaining all life processes.
- 22 March is celebrated as World Water Day.
- World water day is celebrated to make everybody understand about the importance of water.
- Water is important to all living organisms for maintaining all metabolic activities and daily activities.
- Water is important to animals because water is needed for regulation of body temperature, growth, digestion, reproduction, metabolism, excretion.
- Water is also important because it an universal solvent.
- Water provides habitat for various animals in the form of ponds, rivers, seas etc.
- Water forms blood, lymph and other body fluids.
- It transports all waste materials from all the cells to the kidney, skin and lungs for excretion.
- In plants water maintains cell turgidity for structure and growth, transports nutrients throughout the plants, helps in photosynthesis, acts as a raw material of transpiration.
- 50 liters of water is recommended by United Nations required for daily activities.
- One third of the people face water scarcity.
Availability of water
- 71% of water of earth’s surface is covered with water.
- Water is contained on seas, oceans, lakes, rivers, ice caps.
- But most of the water is not fit for human to consume because water of seas and oceans is saline water.
- The only water which is fit for human consumption is fresh water.
- Fresh water represents maximum amount of water present on the earth.
- Amount of ground water is less on the earth if compared to fresh water.
- One fourth of the total water on earth is present in lakes and rivers.
- Water present in glaciers, ice caps, and permanent snow is not readily available.
- Earth appears blue because of the presence of water.
Forms of water
- The circulation of water in various forms is called as water cycle.
- Water circulates in three forms- solid, liquid and gas.
- In solid form water is present as snow, ice, as ice caps in the poles of earth, in mountains, and glaciers.
- In liquid form, water is present in oceans, lakes, rivers, and ground water.
- In gaseous form, water is present as water vapor in the air.
- Water cycle helps to keep water constant on the earth.
Ground water as an important source of water
- Near water bodies the soil is moist under the ground because of the presence of ground water.
- A layer at which the space between particles of soil and gaps between rocks are filled with water, the upper limit of this layer is called water table.
- Ground water is the water found below water table.
- Water table may be at a depth of less than several meters below the ground.
- The process of seeping of rain water and water from other sources into the ground to form ground water is called infiltration.
- Rain water and water from rivers, ponds seep through the soil and fill the gaps between particles of soil and rocks.
- Below the water table, ground water stored between layers of rocks is called as aquifer.
- Hand pumps and tube wells are used to pump out aquifer water.
- Underground water is replenished by seepage of rainwater.
Depletion of water table
- Depletion if water table is caused due to many reasons such as
- Increase in population decreases the open areas required for water seepage due to construction of houses, offices, roads and also the construction works need high amount of water.
- Industries need huge amount of water for production purposes and increasing industries cause depletion of water table.
- Less rainfall also cause less seepage of rain water.
- For agricultural activities farmers need huge amount of ground water for irrigating their crops and thus cause depletion of ground water.
Distribution of water
- Water is distributed unevenly in the whole world.
- For example some places are water rich such as Meghalaya due to heavy rainfall and deserts are dry because of the absence of rainfall.
- Uneven distribution of water causes floods and draughts.
- Heavy rainfall causes flood and less rainfall causes draughts.
Management of water
- Causes of water wastage
- Supply of water should be managed properly to avoid wastage of water.
- Wastage of water take place due to
- Leakage of pipes while supplying water.
- Leaking taps.
- While using water for daily activities water is sometimes wasted.
- Water from rainfall flows away.
- Ways to manage water better
- Water harvesting is the process of recharging ground water with rain water.
- Bawris are the traditional way of water harvesting.
- Bawris are deep wells dug in the ground which have steps to reach the water stored.
- The process of watering the plants at the base with narrow tubings is called drip irrigation.
- Use of water can be managed by turning off the taps while not in use, mopping the floor instead of washing.
Effect of water scarcity on plants
- Plants need water for absorbing nutrients from the soil for photosynthesis.
- Plants wilt and become dry in the absence of water.
- In the absence of water, plants may die and oxygen released by the plants may get depleted and thus causing the death of all organisms.
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