Question

Define freshwater.

Answer 1

Hint: As the name suggests, fresh water would be free from the impurities or contaminants. The three main sources of water for human beings are groundwater, surface water and rain water.

Complete Solution :
Let us know what we exactly mean by fresh water,
Fresh water-
- It is a term to describe the water occurring naturally having low concentrations of dissolved salts. Fresh water can be any source except sea water or brackish water.
- Water is broadly classified as salt water and fresh water. The sources of freshwater are mainly rivers, lakes, reservoirs, streams, etc. Fresh water may include water from ice sheets, glaciers and ice caps. In fact, the majority of freshwater on Earth is in ice caps.
- Fresh water is vital for human lives and also supports ecosystems. It is used in various aspects of life i.e. power generation, sanitisation, food production, etc. But as it is impossible to increase its supply naturally to fulfil the demand, fresh water is scarce.

Numerically, fresh water can be defined as:
The water with less than 500 parts per million (ppm) of dissolved salts is known as fresh water. Other water sources give higher upper salinity limits i.e. 1000 ppm or 3000 ppm.
- It’s alarming to know that only 3% of earth’s water is freshwater, out of which 0.5% is available in liquid and usable form.

Note: Pollution caused by human activities is a threat call for the sources of fresh water as it is a renewable but a finite natural resource.
Chemical contamination of fresh water causes a serious damage to the natural ecosystem.