Question

Which of the following is a source of freshwater?
A. Rain water
B. Groundwater
C. Surface runoff
D. All of the above

Answer 1

Hint: The clouds are formed by the water which evaporated from ponds and lakes. This evaporated water returns to the earth in the form of rainfall and gets stored as groundwater. Rain water, groundwater and surface run-off water are all examples of freshwater.

Complete answer:
The fresh water bodies can be divided into lentic and lotic systems. The lentic water system consists of still water bodies like ponds, lakes and swamp. The lotic water system contains running water sources like groundwater, rain water, run-off water, etc.
Only 2-2.5% of total water is freshwater on earth. Most of the freshwater remains frozen in the ice caps and mountains. Freshwater is generally a renewable source but the reservoirs are limited. The replenishment of freshwater takes place only by the water cycle.
Freshwater can be defined as the water with very low or negligible amount of soluble salts in it. Freshwater should not contain salt more than 500-1000 ppm. Freshwater mostly remains full of impurities and insoluble minerals and metal ions. Therefore, it may not be directly drinkable. Deforestation, water pollution, eutrophication etc. the root cause of exhaustion of freshwater.

Hence, the correct answer is option (D).

Note: The seawater and brackish water are not included under freshwater as they contain high amounts of salts dissolved in them. The water of chalybeate spring is very rich in minerals and is considered a freshwater body. Freshwater can also be obtained from hyporheic zones apart from lentic and lotic water systems. Hyporheic zones consist of large rivers.