Water: A Precious Resource
Water is very important in sustaining life on the earth. 22 March is celebrated as the world water day.
Water provides habitat to several animals and plants. Though 71% of the earth is covered with water but the amount of potable water is less (about 0.006%).
Water exists in three forms namely, solid (in the form of snow or ice), liquid (water in oceans, rivers, lakes etc.) and gaseous (vapours in the air) forms.
Water cycle is rotational order, in which water vapours go to the air by evaporation and transpiration process and form clouds, then comes back to the surface of the earth by condensation and precipitation.
However, water is maintained by the water cycle, yet there is severe shortage of water in many parts of the world. In India, some parts receive excessive rains while some parts have very scanty rainfall.
Water resources are sources of water that are useful or potentially useful to humans. Uses of water include agricultural, industrial, household, recreational and environmental activities.
Groundwater is rain water, which mainly comes from the seepage of water deposited under the ground. It is an important source of water.
The ground water passes through the soil and gets filtrated by several layers of sand and rocks. The ground water can be obtained by digging wells, sinking tube wells, hand pumps etc.
Water table is the level of water under the ground. It varies from place to place. Infiltration is the process of seeping of water into the empty space of the ground.
When the ground water is stored between the layers of hard rocks, which are present below the water table, it is called aquifer.
The excess use of ground water depletes the water-table. However the water table does not get affected as long as it is replenished by natural methods. Increased population, increasing industries, agricultural activities and mismanagement etc. are responsible for the depletion of water.
The various factors that are responsible for the depletion of water table are increasing population, increasing industries and agricultural activities.
Due to increased population, demand of water increases causing depletion of water table. All industries require water. Increasing industries cause depletion of ground water. Rain is the main source of water for irrigation. But irregular rainfall has increased the dependence of farmers on the ground water. So, it depletes ground water.
Water management is a practise to minimise the wastage of water.
Collection and conservation of rainwater from the roof top of buildings and industries is called water harvesting or rain water harvesting. This process leads to rise of water table. This method is encouraged by the government these days for conserving water as this process leads to rise in water table.
Drip irrigation is a technique of using narrow tubings to provide water to plants directly at their base. This helps in conservation of water. Farmers use this technique in the field in order to use water economically.