6 Water Resources
NCERT Questions
- Choose the right answer of the followings from the given options:
(i) Which one of the following types describes water as a resource?
a) Abiotic resources
b) Non-renewable resources
c) Biotech resources
d) Cyclic resources
Ans. d) Cyclic resources
(ii) Which one of the following rivers has the highest replenishable groundwater resources in the country?
a) The Indus
b) The Brahmaputra
c) The Ganga
d) The Godavari
Ans. c) The Ganga
(iii) Which of the following figures in cubic kilometres correctly shows the total annual precipitation in India?
a) 2000
b) 3000
c) 4000
d) 5000
Ans. c) 4000
(iv) Which one of the following South Indian states has the highest groundwater utilization in percentage of its total groundwater potential?
a) Tamil Nadu
b) Karnataka
c) Andhra Pradesh
d) Kerala
Ans. a) Tamil Nadu
(v) 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 irrigation
Ans. a) Irrigation
- Answer the following questions in about 30 words:
(i) It is said that water resources in India have been depleting very fast. Discuss the factors responsible for depletion of water resources.
Ans. Water scarcity is possibly to pose the greatest challenge on account of its increased demand coupled with shrinking supplies due to overutilization and pollution, the per capita availability of water is dwindling day by day due to increase in population. The available water resources are now getting polluted with industrial, agricultural and domestic effluents, and this in turn is further limiting the availability of usable water resources.
Some states utilise large proportion of their groundwater potential which has resulted in groundwater depletion in these states. Over withdrawals in some states like Rajasthan and Maharashtra has increased fluoride content concentration in groundwater and this practice has led to increase in concentration of arsenic in parts of West Bengal and Bihar.
Water gets polluted by foreign matters such as micro-organisms, chemicals, industrial, domestic and other wastes. When toxic substances enter lake, streams, rivers, oceans and other water bodies, they get dissolved or lie suspended in water. This results in pollution of water whereby quality of water deteriorates affecting aquatic systems. Sometimes these pollutants also seep down and pollute groundwater. The Ganga and Yamuna are the two highly polluted rivers in the country.
(ii) What factors are responsible for the highest groundwater depletion in the states of Punjab, Haryana and Tamil Nadu?
Ans. The states of Punjab, Haryana and Tamil Nadu have agriculture supported mainly by irrigation water and the main source for it is the underground water. These regions were the target regions for Green Revolution. All the Green revolution crops are water intensive. Hence, the demand for water in these states is very high. These regions have soft alluvial soil which allows the rainwater to seep down and recharge the underground water table. The land is easy to dug hence extraction of underground water is easiest source of water.
It has also been found that irrigated lands have higher agricultural productivity than un-irrigated land. Further, the high yielding varieties of crops need regular moisture supply which is made possible only by a developed irrigation system. In Punjab, Haryana and western Uttar Pradesh, more than 85% of their net sown area is under irrigation. Wheat and rice are grown mainly with the help of irrigation in these states. Of the total net irrigated area, 76.1% in Punjab and 51.3% in Haryana are irrigated through wells and tube wells. This shows that these states utilise large proportion of their groundwater potential which has resulted in groundwater depletion in these states. The overuse of groundwater resources has led to 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?
Ans. At present, the agriculture use accounts for the highest share of utilization for both ground and surface water resources. The main reason being that the agricultural accounts for the largest share in economy of the country but in recent times the share of secondary and tertiary activities has been rising in the economy. This in turn will reduce the share of agriculture and increase the share of industrial and domestic sector in the consumption of all resources, including water resources of the country.
(iv) What can be possible impacts of consumption of contaminated/unclean water on the people?
Ans. Water constitutes a large proportion of human body. Water intake is an essential part of human life. Contaminated water intake is one of the biggest reasons of many chronic diseases. The intake of contaminated water is the cause of severe water borne diseases and is also one of the main causes of high infant mortality rates. The contaminated water is the reason for several diseases like cholera, typhoid etc. which are the major killer diseases in India.
- 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.
Ans. India accounts for about 2.45% of world’s surface area, 4% of the world’s water resources and about 16% of the world’s population. The total water available from precipitation in the country in a year is about 4000 cubic km. The availability from surface water and replenishable ground water is 1,869 cubic km. Out of this, only 60% can be put to beneficial uses. Due to topographical, hydrological and other constraints, only about 690 cubic km (32%) of the available surface water can be utilised. Water flow in a river depends on size of its catchment area or river basin and rainfall within its catchment area.
Precipitation in India has very high spatial variation and it is mainly concentrated in monsoon season. Rivers in the country like the Ganga, the Brahmaputra and the Indus have huge catchment area and precipitation is also relatively high. These rivers although account for only about 1/3 of the total area in the country, have 60% of the total surface water resources. Moreover, Himalayan Rivers are glacier fed perennial, various southern rivers are rain fed seasonal rivers. Much of the annual water flow in the 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 Ganga basin.
Groundwater Resources: The total replenishable groundwater resources in the country are about 432 cubic km. The level of groundwater utilization is relatively high in the river basin lying in the North Western region and parts of South India, the groundwater utilization is very high in the states of Punjab, Haryana, Rajasthan and Tamil Nadu. However, there are states like Chhattisgarh, Odisha, Kerala etc. which utilise only a small proportion of their groundwater potentials. States like Gujarat, Uttar Pradesh, Bihar, Tripura and Maharashtra are utilising their groundwater resources at a moderate rate.
Lagoons and backwaters: India has a vast coastline and quite a few coasts are much intended in some states. Due to this, number of lagoons and lakes has been formed. The states like Kerala, Odisha and West Bengal have lost surface water resource in these lagoons and lakes. Water is generally used for fishing and irrigating certain varieties of paddy crops, coconut, etc.
Surface water resources: There are four major sources of surface water. These are rivers, lakes, ponds and tanks. In the country, there are about 10,360 rivers and their tributaries longer than 1.6 km each. The mean annual flow in all the river basins in India is estimated to be 1,869 cubic km.
(i) The depleting water resources may lead to social conflicts and disputes. Elaborate it with suitable examples.
Ans. It can be said with some certainty that the societies will witness demographic transition, geographical shift of population, technological advancement, degradation of environment and water scarcity. Water scarcity is possibly to pose the greatest challenge on account of its increased demand coupled with shrinking supplies due to overutilization and pollution. Water is a cyclic resource with abundant supplies on the globe. Approximately 71% of the Earth’s surface is covered with it. But fresh water constitutes only about 3% of the total water.
In fact, a very small proportion of fresh water is effectively available for human use. The availability of fresh water varies over space and time. The tension and disputes on sharing and control of this scarce resource are becoming contested issues among communities, regions and states.
India accounts for 2.45% of world’s surface area, 4% of water resources and about 16% of population. The total utilizable water resource in the country is only 1,122 cubic km. This dearth of utilizable water has caused several disputes in India at local, state and national levels. Sadly, in India there is a conflict on issues like social structure (caste ism, communalism etc).
Rivers of northern India have condition of water surplus and many regions face flood situation whereas the rivers in southern India have perennial flow concentrated in the months of monsoon leading to water scarcity during the rest of the year. To solve the situation there have been many proposed river linkage schemes which became causes for disputes among the states over the sharing of water resources.
It is the scarcity of water that caused long standing disputes between the state of Karnataka and Tamil Nadu over sharing of waters of Kaveri River. Sharing of water of Brahmaputra has always been a cause of conflict between India and Bangladesh. Much to India’s dislike and concern China is planning to build a dam on river Brahmaputra.
(iii) What is watershed management? Do you think it can play an important role in sustainable development?
Ans. 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. However, in broad sense, watershed management includes conservation, regeneration and judicious use of all resources natural like land, water, plants and animals, and human within a watershed. 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. In short, community is the soul of the entire scheme.
Watershed management not only conserves the entire ecosystem of an area but also empowers the people by making them socially and economically self-reliant as it has community participation its vital component. Since local people understand the local ecosystem in the best way, therefore they conserve in the best way. Sustainable development is the development which fulfils the needs of present generation without depriving the future generations from the benefits arising from the resources.
The Importance of watershed management in sustainable development has been identified and many programs both by government and NGOs have been launched for the watershed management:
Such examples are ‘Hariyali’ 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 project is being executed by gram panchayats with people’s participation.
‘Neeru-Meeru’ (Water and You) programme in Andhra Pradesh and ‘Arvary Pani Sansad’ in Alwar, Rajasthan have taken up constructions of various water harvesting structure such as percolation tanks dug out ponds (johad), check dams etc. through people’s participation.
Tamil Nadu has compulsory water harvesting structures in the houses. No building can be constructed without making structures for water harvesting.
—x—x—x—