Class Ten Geography Chapter 2 NCERT Solutions
Chapter 3: Water Resource
TEXTBOOK EXERCISES
1. Multiple Choice Questions.
(i) Based on the information given below classify each of the situations as ‘suffering from water scarcity’ or ‘not suffering from water scarcity’.
(a) The region with high annual rainfall.
(b) The region having high annual rainfall and a large population.
(c) The region having high annual rainfall but water is highly polluted.
(d) The region having low rainfall and low population.
Ans. (a) Not suffering from water scarcity. (b) Not suffering from water scarcity.
(c) Suffering from water scarcity. (d) Suffering from water scarcity.
(ii) Which one of the following statements is not an argument in favour of multi-purpose river projects?
(a) Multi-purpose projects bring water to that area which suffers from water scarcity.
(b) Multi-purpose projects by regulating water flow help to control floods.
(c) Multi-purpose projects lead to large-scale displacements and loss of livelihood.
(d) Multi-purpose projects generate electricity for our industries and our homes.
Ans. (c) Multi-purpose projects lead to large-scale displacements and loss of livelihood.
(iii) Here are some false statements. Identify the mistakes and rewrite them correctly.
(a) Multiplying urban centres with large and dense population and urban lifestyles have helped in proper utilisation of water resources.
(b) Regulating and damming of rivers do not affect the river’s natural flow and its sediment flow.
(c) In Gujarat, the Sabarmati basin farmers were not agitated when higher priority was given to water supply in urban areas, particularly during droughts.
(d) Today in Rajasthan, the practise of rooftop rainwater water harvesting has gained popularity despite high water availability due to the Rajasthan Canal.
Ans. (a) Multiplying urban centres with large and dense population and urban lifestyles have not only added to water and energy requirements but have further aggravated the problems.
(b) Regulating and damming of rivers affect the river’s natural flow causing poor sediment flow.
(c) In Gujarat, the Sabarmati basin farmers were agitated and almost caused a riot when higher priority was given to water supply in urban areas, particularly during droughts.
(d) Today in Rajasthan, the practise of rooftop rainwater harvesting is on the decline on account of high water availability due to Rajasthan Canal.
2. Answer the following questions in about 30 words.
(i) Explain how water becomes a renewable resource.
(ii) What is water scarcity and what are its main causes?
(iii) Compare the advantages and disadvantages of multi-purpose river projects.
Ans. (i) Water becomes a renewable resource due to the hydrological or water cycle. In this cycle – due to heat of the sunlight – water in oceans, rivers and lakes evaporates and forms water vapour. The water vapour rises and condenses in the higher atmosphere and falls in the form of precipitation – snow, rain or hail. Rainwater seeps in the ground or there is surface runoff to rivers and lakes, these water bodies are again replenished. Thus, a cycle is completed and we get water as a renewable resource.
(ii) Water scarcity is the shortage in the availability of usable water resource. The availability of water varies over space and time. This is due to variations in seasonal and annual precipitation. The main reasons for the scarcity of water are.
(a) Increase in population, which leads to greater demand for water for domestic use. The rise in population also necessitates an increase in agricultural activities. This also needs more water.
(b) Industrialisation leads to greater demand for water for different needs. Power demand increases, water is also needed in generating power in hydro-power projects.
(c) Urbanisation is increasing the world over and so is the demand for water. People in urban areas bore tube wells to get groundwater. This has further worsened the availability of water.
(d) Bad quality of water automatically puts pressure on its availability. Domestic and industrial water wastage directly flows into rivers making them polluted.
(e) In villages, towns and cities all the people do not have equal access to water. The rich and powerful section of society gets a larger share of water than other sections.
(iii) Advantages. Multipurpose river projects provide us with multiple benefits like (a) water for irrigation (b) hydroelectricity for our industries and homes (c) water for domestic and industrial use; regulating flow of water and helping (d) flood control (e) recreational facilities (f) inland navigation and (g) pisciculture. Disadvantages. However, multipurpose river projects have come under greater scrutiny in recent times because of (a) their failure to fulfil their basic objectives like flood control. (b) Regulating and damming of rivers affect the natural flow of the rivers, cause exessive sedimentation and adversely affect aquatic life. (c) The reservoirs that are created in the floodplains overflow and submerge the existing vegetation and soil. (d) Multipurpose projects lead to large-scale displacement of local communities and the loss of their livelihood (e) Excessive use of water and overirrigation on account of the projects lead to land degradation and cause waterborne disease, pests and pollution.