Microscopy techniques play a crucial role in many Biology Topics, allowing for detailed observations of cells and tissues.
Explain the Factors Responsible for the Depletion of Water Table
The water which we draw (or take out) from under the ground for various purposes gets replenished naturally by the seepage of rainwater. The water table at a place does not get affected (or does not get depleted) as long as we draw as much groundwater as is replenished by natural processes like seepage of rainwater. The water table at a place may, however, get depleted and go down if the water drawn from the ground by us is not sufficiently replenished naturally. Some of the factors which affect the water table (or deplete the water table) at a place and make it go down are :
- Increase in population
- Industrial and agricultural activities
- Scanty rainfall
- Deforestation, and
- Decrease in the effective area for seepage of rainwater.
We will now explain the various factors which are responsible for the depletion of water table in somewhat detail, one by one.
1. Increasing Population
The increasing population needs more and more water for its day to day activities. As the population is increasing, more houses, shops, offices, schools, industries, roads and pavements, etc., need to be constructed. A huge amount of water is required for the construction work. Usually, groundwater is used for construction work. This leads to the consumption of a lot of groundwater.
Now, when more and more houses, shops, offices, schools, industries, roads and pavements, etc., are constructed, then the open spaces like parks and playgrounds having unpaved ground for the seepage of rainwater into ground are reduced. This decreases the seepage of rainwater into the ground. So, due to increasing population, on the one hand we are consuming more groundwater and on the other hand we are allowing less rainwater to seep into the ground. This leads to the depletion of water table. In fact, the water table in some parts of many cities has gone down to very low levels (because such parts of cities have hardly any ‘unpaved ground’ for the seepage of rainwater into the ground).
2. Increasing Industries
Industries produce (or make) a large number of various types of things which we use in our everyday life. Almost everything that is made in industries needs water at some stage during its production process. Due to this, water is used by all the industries. As the population is increasing, the demand for various industrial goods is increasing, and hence the number of industries is also increasing continuously. Water used by most of the industries is drawn (or pumped out) from the ground. As the number of industries is increasing, the water drawn from the ground for their use is also increasing. This results in the depletion of water table.
3. Agricultural Activities
The growing of various crops in agriculture requires a lot of water for irrigation. In India, a majority of farmers depend on rains for irrigating their crops. Irrigation systems such as reservoirs, dams and canals exist in some places but these irrigation systems usually get their water supply from rains. So, in the times of erratic rainfall (irregular rainfall) or scanty rainfall (inadequate rainfall), the farmers have to use groundwater for the irrigation of their crops. As more and more food has to be grown for the increasing population, the use of groundwater for agriculture is increasing day by day. This leads to the depletion of water table.
4. Scanty Rainfall
‘Insufficient rainfall’ is called scanty rainfall’. Sometimes there is scanty rainfall during the rainy season. Since there is less rainfall, less rainwater seeps into the ground. In such a situation, much more groundwater is drawn out by the people for various purposes than gets replenished by rainfall. This results in depletion of water table.
The cutting down of trees and plants from the forest for various purposes is called deforestation. We know that forests help in bringing rain (by putting a lot of water vapour into air through transpiration). So, lesser number of trees and plants in the forest will bring less rainfall. The trees and plants of forests also help in the seepage of rainwater into the ground. If there are lesser number of trees and plants in the forest, less rainwater will seep into the ground. So, deforestation leads to lesser rainfall as well as lesser seepage of rainwater into the ground. This depletes the water table.
6. Decrease in Effective Area for Seepage of Rainwater
Due to increasing urbanisation and industrialisation, more and more space is being covered by houses, other buildings, roads and pavements, etc., and the open spaces having unpaved ground are getting reduced day by day. It is the ‘unpaved ground’ which lets the raimVater seep into the ground and recharge water table. Since the effective area for seepage of rainwater (such as unpaved ground) in urban areas is decreasing day by day, less and less rainwater seeps into the ground. This leads to the depletion of water table.