Question

Water harvesting is done by ____________ processes.
[A] Rainwater
[B] Groundwater
[C] Both [A] and [B]
[D] Atmospheric water

Answer 1

Hint: To answer this, remember that harvesting of water means the storage of run-off or free flowing water. The water is stored in reservoirs or tanks and is used for other purposes like irrigation etc. You can use this to answer the given question.

Complete answer:
To answer this, firstly let’s understand the definition of the term water harvesting.
We use the term ‘water-harvesting’ to explain storing of run-off water without polluting it so that we can use it safely for other purposes.
There are several methods that capture run-off rainwater from rooftops, local catchments, seasonal flood from nearby streams etc. and this provides water for irrigation, drinking, reduce seawater ingress, storm water discharge, overloading of sewage treatment plants and also to increase ground water recharge.
Now let us discuss the methods used for harvesting of water.
There are two major processes that we use for water harvesting. They are rainwater harvesting and ground – water harvesting. Now, let us briefly discuss these processes.
Rainwater harvesting – It is basically a method of collection as well as storage of water that falls in the form of rain in tanks or even natural reservoirs. After storing, the water is treated in water treatment plants where the acidity is checked and maintained and other quality tests are carried out.
Groundwater harvesting – It is also a method of storing run-off water. It is a process where the water present under the ground is saved by controlling flow in the aquifer and raising the water table.
From the above discussion we can understand that water harvesting is done by rainwater and groundwater harvesting processes.

Therefore, the correct answer is option [C] Both [A] and [B] .

Note:
Rainwater and groundwater harvesting are the major and the most common processes used for harvesting water. However, recent research has shown that harvesting of atmospheric water is possible too.
Certain moisture harvesters capture vapour present in air by absorption or adsorption where the water molecules stick to the hygroscopic material by means of chemical and physical absorption. However, it is not common due to the high vaporization enthalpy which is needed for the dehydration of water molecules from the material