NCERT Solutions Class 12 Geography Chapter 4 Water Resources

1. Choose the right answers of the following from the given options.

(i) Which one of the following types describes water as a resource?
(a) Abiotic resource
(b) Non-renewable Resources
(c) Biotic Resource
(d) Cyclic Resource

Answer : D

(ii) Which one of the following south Indian states has the highest groundwater utilisation (in per cent) of its total ground water potential?
(a) Tamil Nadu
(b) Karnataka
(c) Andhra Pradesh
(d) Kerala

Answer : A

(iii) The highest proportion of the total water used in the country is in which one of the following sectors?
(a) Irrigation
(b) Industries
(c) Domestic use
(d) None of the above

Answer : A

2. Answer the following questions in about 30 words:

(i) It is said that the water resources in India have been depleting very fast. Discuss the factors responsible for the depletion of water resources?
Answer : The per capita availability of water is dwindling day by day due to the increase in population. The available water resources are also getting polluted with industrial, agricultural, and domestic effluents, and this, in turn, is further limiting the availability of usable water resources. Some states utilise a large proportion of their groundwater potential which has resulted in groundwater depletion in states like Punjab, Haryana, and Uttar Pradesh.

(ii) What factors are responsible for the highest groundwater development in the states of Punjab, Haryana and Tamil Nadu?
Answer : The states of Punjab, Haryana, and Tamil Nadu have agriculture supported mainly by irrigated water and the main source for it is underground water. These regions were the target regions for the green revolution. All the green revolution crops are water-intensive, hence the demand for water in these states is very high. Groundwater is overutilised in these states for the purpose of irrigation which has led to the decline in groundwater table in these states.

(iii) Why the share of agricultural sector in total water used in the country is expected to decline?
Answer : In recent times the share of secondary and tertiary activities has been rising in the economy. This will reduce the share of the agricultural sector and increase the share of the industrial and domestic sector in the consumption of all resources including the water resources of the country.

(iv) What can be possible impacts of consumption of contaminated/unclean water on the people?
Answer : Contaminated water intake is one of the biggest reasons for many chronic diseases. The intake of contaminated water is the cause of severe water borne disease and is also one of the main causes of high infant mortality rates. Contaminated water is the reason for several diseases like Cholera, typhoid, etc. which are among the major and common diseases in India.

3. Answer the following questions in about 150 words.

(i) Discuss the availability of water resources in the country and factors that determine its spatial distribution?
Answer : India accounts for about 2.45 per cent of the world’s surface area, 4 per cent of the world’s water resources and about 16 per cent of the world’s population. The total water available from precipitation in the country in a year is about 4,000 cubic km. The availability from surface water and replenishable groundwater is 1,869 cubic km. Out of this, only 60 per cent can be put to beneficial uses. Thus, the total utilisable water resource in the country is only 1,122 cubic km.
Factors that determine its spatial distribution:
• Water flow in a river depends on size of its catchment area or river basin and rainfall within its catchment area.
• Precipitation is mainly concentrated in Monsoon season.
• The precipitation is relatively high in the catchment areas of the Ganga, the Brahmaputra and the Barak rivers, these rivers, although account for only about one-third of the total area in the country, have 60 per cent of the total surface water resources. 
• The annual water flow in south Indian rivers like the Godavari, the Krishna, and the Kaveri has been harnessed, but it is yet to be done in the Brahmaputra and the Ganga basins.

(ii) The depleting water resources may lead to social conflicts and disputes. Elaborate it with suitable examples?
Answer : Water is a cyclic resource with abundant supplies on the globe. Approximately, 71 per cent of the earth’s surface is covered with it but freshwater constitutes only about 3 per cent of the total water. In fact, a very small proportion of freshwater is effectively available for human use.
The availability of freshwater varies over space and time. The tensions and disputes on sharing and control of this scarce resource are becoming contested issues among communities, regions, and states.
• The sharing of waters of rivers of Punjab, Haryana, Himachal Pradesh is a contesting issue.
• Since long, the dispute is going on between Tamil Nadu and Karnataka over the waters of Kaveri River.
• The sharing of waters of Narmada Basin is a dispute between the states of Maharashtra, Madhya Pradesh and Gujarat.

(iii) What is watershed management? Do you think it can play an important role in sustainable development?
Answer : Watershed management basically refers to efficient management and conservation of surface and groundwater resources with community participation. It involves prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks, recharge wells, etc. Watershed management aims at bringing about balance between natural resources on the one hand and society on the other. The success of watershed development largely depends upon community participation. The Project is being executed by Gram Panchayats with people’s participation:
• Haryali is a watershed development project sponsored by the Central Government which aims at enabling the rural population to conserve water for drinking, irrigation, fisheries and afforestation. The Central and State Governments have initiated many watershed development and management programmes in the country:
• Neeru-Meeru (Water and You) programme (in Andhra Pradesh) and Arvary Pani Sansad (in Alwar, Rajasthan) have taken up constructions of various water-harvesting structures such as percolation tanks, dug out ponds (Johad), check dams, etc., through people’s participation.