Water Table, Infiltration And Aquifer

GROUND WATER AS AN IMPORTANT SOURCE OF WATER

If we dig a hole in the ground near a water body we may find that the soil is moist. The moisture in the soil indicates the presence of water underground. If we dig deeper and deeper, we would reach a level where all the space between particles of soil and gaps between rocks are filled with water (Fig. 16.7). The upper level of this layer is called the water table. The water table varies from

Fig. 16.6 Women fetching water

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. What is the source of this 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 handpumps.

Have you ever been to a site where construction work is going on? From

where do the workers get water for construction? May be you have seen boring being done at such sites to reach the water table. Enquire from the people working there how deep they have to dig. Can we keep on drawing water from under the ground? How will it affect the water table?