Ans
1) 68.7% of the fresh water on Earth is trapped in glaciers. 30% of fresh water is in the ground. 1.7% of the world's water is frozen and therefore unusable. Approximately 400 billion gallons of water are used in the United States per day
2)Water keeps on circulating in nature through various states of matter; in the form of liquid, vapor and ice. Due to this, the water which disappears because of evaporation comes back in the form of rain. Thus, water becomes a renewable resource.
3)Scarcity of water means shortage of water, an imbalance between demand and supply. Causes or the factors responsible for water scarcity are as follows:
1. growing population which is the main cause of water scarcity.
2. urbanization and industrialization which have increased the consumption of water.
3. wastage and injudicious use of water.
4. over-exploitation and mismanagement of water resources.
5. unequal access to water resources.
6. in post green revolution era, the commercial crops which are grown more, consume more water.
4)We cannot live without water. Saving water helps to preserve our environment. It reduces the energy required to process and deliver water, which helps in reducing pollution and in conserving fuel resources. Saving water now means having water available in the future for recreational purposes, too.
5)Hydrologists typically assess scarcity by looking at the population-water equation. An area is experiencing water stress when annual water supplies drop below 1,700 m3 per person. ... Water scarcity is a relative concept and can occur at any level of supply.
6)dam is defined as a barrier or structure across a stream, river or waterway to confine and then control the flow of water. ... Dams are structures built to retain water by forming a reservoir behind the structure. These are usually built across, or near, naturally flowing water to manage the water for human use.
7)multipurpose project is that which simultaneously serves several purposes. A dam built across a river often serves more than one purpose at a time and is termed as a multipurpose project.
8)Rainwater harvesting system, also called rainwater collection system or rainwater catchment system, technology that collects and stores rainwater for human use. Rainwater harvesting systems range from simple rain barrels to more elaborate structures with pumps, tanks, and purification systems.
9) Rooftop Rain Water Harvesting is the technique through which rain water is captured from the roof catchments and stored in reservoirs. Harvested rain water can be stored in sub-surface ground water reservoir by adopting artificial recharge techniques to meet the household needs through storage in tanks.

Ans 1.
million people lack access to safe water supply

The water and sanitation crisis claims more lives than any disease .

in water scarcity areas Women spend 200 million hours a day collecting water.

A man taking a five-minute shower uses more water than a person living in village area

The Niger delta hosts about 20% of Mali’s population and generates on average 90,000 tonnes of fish catch per year.

Wetlands and their wildlife are a key part of the global tourism experience. Expenditure by tourists visiting wetlands is estimated at around US$ 925 billion each year.

Asia’s lower Mekong delta supports the world's most productive inland fisheries, providing 56 million people with up to 80% of their animal protein intake and valued at around US$ 3 billion per year.

Thirty three of the world’s 105 largest cities derive their drinking water from catchments within forest protected areas such as national parks and santuries

management of the Australian city of Melbourne’s forested catchments (almost half of which are protected areas) is being adapted in the face of climate change to minimise impacts on water supplies.In 
India, eco-development programmes around Ranthambore Tiger Reserve in Rajasthan have combined conservation and famine relief funds to restore ancient step wells, providing new water supplies for communities, livestock and wildlife.


Ans2. Water becomes a renewable resource as it is renewed by the process of water cycle but over using of ground water(not sea water) can cause depletion of its level


Ans 3. Water scarcity is a condition in which fresh water resources are unable to fulfill the needs of water

It occurs due to the the following factors
.overuse of water
.misue of water
.wastage of water
.pollution of fresh water resources
.deforestation etc.

Ans4. We need to conserve water in order to prevent it to be wasted and to prevent( fresh water resources ) water to be exhausted

Ans6.Dams are the sites for generating electricity and controlling the flow of river water to prevent flooding. these are built on the rivers.


Ans.7 A multi purpose project is a project that consists many goals that are achieved by building or establishing something.
For eg: Sanctuary-- protects flora and fauna as well as prevent them from getting endangered or extinct

Ans8. Rainwater harvesting is , collecting rain water at a place and then using it as in irrigation or for other purpose.

Ans 9. Rooftop rainwater harvesting is collecting rain water from the roof to a pit then it could be used to irrigate the fields OR reacharge the ground water