Groundwater as an Important Source of Water

Ever wondered how people obtain water where it doesn’t rain? Or where there are no sources of fresh water such as a lake, a river, a pond, etc? They usually obtain water from the ground. Let’s find out more about Groundwater as an Important Source of Water.

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Introduction to Groundwater

Groundwater is water that gets collected beneath the surface of the earth. The water seeps through the surface and the mud soaks it. Groundwater is procured by drilling or digging a well or by pumping. However, overpumping of groundwater shouldn’t be done as it affects the salinity of the soil. It reduces the water level and increases the salinity of the soil.

Groundwater is often cheaper, more convenient and less vulnerable to pollution than surface water. Therefore, it is commonly used for public water supplies.

Aquifer

An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted using a water well. It is a porous substrate.  When water can flow directly between the surface and the saturated zone of an aquifer, the aquifer is unconfined. The deeper parts of unconfined aquifers are usually more saturated since gravity causes water to flow downward.

Infiltration

Infiltration is a process where the water on the surface seeps into the soil and enters it. The Infiltration rate is a measure of the rate at which soil is able to absorb rainfall or irrigation.

Water Table

The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. Water that collects or flows beneath the Earth’s surface, filling the porous spaces in soil, sediment, and rocks. Groundwater is formed due to rain and melting of snow, it is also a source of water for aquifers, springs, and wells.

Questions For You

Q1. The water table is :

1. the upper level of an underground surface in which the soil or rocks are permanently saturated with water.
2. the upper level of an underground surface in which the soil or rocks are unsaturated with water.
3. a lower level of an underground surface in which the soil or rocks are permanently saturated with water.
4. the lower level of an underground surface in which the soil or rocks are unsaturated with water.

Sol: The correct answer is option ”a”. The water table is also known as groundwater table in which water seeps into the ground and move downward till it reaches the stage of saturation. The velocity at which water flows underground depends on the permeability of the rocks.

Q2. Groundwater gets recharged by the process of :

1. pumping
2. heavy rainfall
3. infiltration
4. none of the above

Sol: The correct answer is option ”c”.