Question

Which of the following is a source of freshwater?
(a) Rainwater
(b) Groundwater
(c) Surface run-off
(d) All of the above

Answer 1

Hint: The water evaporated from ponds and lakes rise in the sky forming clouds. These clouds in return, drain water in the form of rainfall which gets stored as groundwater.
Rainwater, groundwater, and surface run-off water are all examples of freshwater.

Complete answer: 1. Freshwater can be defined as the water that has an extremely low or negligible amount of soluble salts in it. It should not contain salt more than 500-1000 ppm (parts per million).
2. It mostly remains full of impurities and insoluble minerals and metal ions. Therefore, it may not be directly drinkable.
3. The freshwater bodies can be divided into ‘lentic’ and ‘lotic’ systems. The lentic system consists of still water bodies like ponds, lakes, and swamp. The lotic system contains running water sources like groundwater, rainwater, run-off water, etc.
4. Only 2-2.5% of the total water present on earth is freshwater. Most of the freshwater remains in a frozen state in the ice caps and mountains.
5. Freshwater is generally a renewable source but the reservoirs are limited. The replenishment of freshwater takes place only by the water cycle.
6. Deforestation, water pollution, eutrophication, etc. the root causes of exhaustion of freshwater.
So, the correct answer is ‘All of the above'.

Note:
1. The seawater and brackish water are not included under freshwater as they have a high amount of salts dissolved in them.
2. The water of ‘chalybeate spring' is very rich in minerals and is considered a freshwater body.
3. Apart from the lentic and the lotic system, freshwater can also be obtained from hyporheic zones which consist of large rivers.