# NIOS Class 12 Geography Chapter 21 Our Water Resources

NIOS Class 12 Geography Chapter 21 Our Water Resources, Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Geography Chapter 21 Our Water Resources and select need one. NIOS Class 12 Geography Chapter 21 Our Water Resources Question Answers Download PDF. NIOS Study Material of Class 12 Geography Notes Paper 316.

## NIOS Class 12 Geography Chapter 21 Our Water Resources

Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Geography Chapter 21 Our Water Resources, NIOS Senior Secondary Course Geography Solutions for All Chapter, You can practice these here.

### Our Water Resources

Chapter: 21

GEOGRAPHY

INTEXT QUESTION 21.1

Q.1. What is the main source of surface water?

Ans. Precipitation is the main source of surface water.

Q.2. In which river basin in usable underground water available?

Ans. Plains of Ganga-Brahmaputra.

Q.3. How much part of the country comes under floods and drought every year?

Ans. One-eight part of the country is flood prone and one-sixth is under the grip of drought.

INTEXT QUESTIONS 21.2

Q.1. Define the water budget.

Ans. Water budget means the balance between the available water in the country and water under use.

Q.2. State two units of measurement of water?

Ans.(i) Cubic metre and

(ii) Hectare metre.

Q.3. In which part of the country is the duration of rainfall longest?

Ans. The western coast.

Q.4. What is the proportional share of land area in the country which receive more then 200 cm rainfall?

Ans. It is 8 percent.

Q.5. Mention the main component responsible for the uneven distribution of water.

Ans. Uneven distribution of rainfall is responsible for the uneven distribution of surface and underground water.

INTEXT QUESTIONS 21.3

Q.1. How much is the per capita average annum availability of water in India?

Ans. 1829 cubic metre per person in 2001.

Q.2. When arises the water crisis?

Ans. The water crisis arises when the per capita availability of water falls 100000 metres annually.

Q.3. Which is the main means of irrigation in India? How much percent of land is irrigated by this?

Ans. Wells and tubewells are the main means of irrigation in India. 57% (1997-98) of land is irrigated by this means.

Q.4. In which part of the country is the irrigation done mainly by tanks?

Ans. Peninsular plateau.

INTEXT QUESTIONS 21.4

Q.1. What is called rain water reserve?

Ans. Total amount of rain water recovered in an area is called rain water reserve.

Q.2. Name any two methods of rain water harvesting.

Ans. (i) Construction of potholes.

(ii) Construction of trenches, use of wells, handpump.

Q.3. Which are the main objectives of river Valley projects?

Ans. Flood control, control on soil erosion, water for irrigation and drinking, water for industries.

INTEXT QUESTIONS 21.5

Q.1. Mention any four problems related to the planning and practice of water resources.

Ans. (a) Continued nutrition of atmosphere.

(b) Proper transfer and rehabilitation of men and animals.

(c) Health.

(d) Security and dams.

Q.2. Which are the three factors of water pollution?

Ans. These are:

(a) Domestic waste water.

(b) Industrial effluents.

(c) Chemicals used in agriculture.

Q.3. How much amount was spent by 2000 on watershed development by the government of India in our country?

Ans. 20 billion dollars.

Q.4. Why and when was constituted the National Water Development Authority?

Ans. It was constituted in 1982 to solve the problem of drought and flood.

Q.5. How many river linkages have been identified by the National Water Development Authority?

Ans. 30 rivers.

TERMINAL QUESTIONS

Q.1. Answer the following questions in brief:

(i) What is the meaning of water resources?

Ans. The meaning of water resources is that the water is the most valuable source of nature.

(ii) Mention the main sources of surface water:

Ans. The main sources of surface water are:

1. Rivers.

2. Ponds.

3. Lakes.

4. Oceans.

(iii) Why is more underground water is available in the Northern great plains of the country?

Ans. The more underground water is available in the Northern great plains because the availability of surface water is large in the plains Ganga-Brahmaputra rivers.

(iv) Explain the objectives of river valley projects.

Ans. The objectives of river Valley projects are:

1. Flood control.

2. Prevention of soil erosion.

3. Provision of water for irrigation, drinking and for industries.

4. Generation of electricity.

5. Transport and entertainment.

6. Conservation of wildlife.

7. Development of fisheries.

(v) State the meaning of rain water harvesting.

Ans. Rain water harvesting generally means the collection of rain water. It’s special meaning is a technique of recharging in underground water.

(vi) Explain the meaning of watershed.

Ans. Meaning of watershed refers to an area whose water flows towards a point. The related area may be village or a group of villages in the form of a unit.

(vii) Mention three stages of river linkages.

Ans. Large area of the country suffer from drought and floods. The National Water Development Authority has recommended starting of work on 6 places of river linkages and their completion has to be carried out in three stages. These are:

Ist stage: In the first stage, men peninsular rivers-Mahanadi, Godavari, Krishna and Kaveri have been included.

IInd Stage: In the second stage, linking of small river basins of peninsular India have been recommended. Ken, Betwa and Par-Tapi rivers are included in this.
IIIrd stage: In the third stage, there is a provisions for linking the tributaries of Ganga and Brahmaputra with one another.

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