Q.1. Why has the water shortage problem aggravated in post-independence India?
Ans. Intensive industrialisation and urbanisation witnessed in post-independence India have significantly contributed to the exploitation of available freshwater resources. Industries require huge supply of water for production, cooling of machineries and for power supply in form of hydroelectricity. Ever increasing urban centres with large and dense population and urban lifestyles have increased the domestic water requirement and power requirement. Individual groundwater pumping devices in housing complexes of big cities have aggravated the problem of depletion of water resources. Agricultural progress in the post-independence era has also led to water scarcity. Irrigation in different forms to increase agricultural production exploits the available surface and groundwater sources excessively. As a result of the above mentioned reasons the water shortage problem has aggravated in post independence India.
Q.2. Why should we conserve and manage our water resources? How can we control overexploitation and mismanagement of water resources? State any two points that should be kept in mind for efficient management of water.
Ans. We should conserve and manage our water resources to safeguard ourselves from health hazards, to ensure food security as well as for continuation of our livelihood and productive activities. Taking into consideration the problem of water scarcity and decreasing freshwater resources, the need of the hour is to conserve and manage our water resources. Over-exploitation and mismanagement of water resources can be controlled through conservation and management of water resources. Conservation can also prevent degradation of our natural ecosystem as well as control the ecological crisis that may arise due its scarcity.
Two points that should be kept in mind for efficient management of water are :
(i) Prevention of water pollution, so that available water sources are not rendered unusable.
(ii) Integrated Water Resource Management should develop water saving technology and recycling and reuse of water. Rainwater harvesting should be promoted.
Q.3. Mention a negative effect of irrigation? How can irrigation transform the social landscape?
Ans. Irrigation has changed the cropping pattern of many regions with farmers shifting to cultivation of water intensive and commercial crops. This has great ecological consequences. It leads to water logging and consequent salinisation of the soil. This is a negative effect of irrigation. As rich farmers have better access to irrigation they have earned more money due to the production of commercial crops. On the other hand, the landless poor who couldn’t avail of its benefit, became poorer. Thus, irrigation has transformed the social landscape by increasing the social gap between rich landowners and the landless poor farmers.
Q.4. Give examples of traditional water harvesting system prevalent in various parts of India.
Ans. Traditional water harvesting system prevalent in various parts of the India include the following methods :
(i) Diversion channels like ‘guls’ and ‘kuls’ of Western Himalayas are built in hilly and mountain areas for irrigating agricultural fields.
(ii) In hilly areas of Meghalaya, bamboo-drip irrigation system taps stream and spring water.
(iii) Inundation channels are constructed to irrigate agricultural fields in the floodplains of Bengal.
(iv) In the arid regions of Rajasthan agricultural fields were converted into rainfed storage structures locally known as ‘Khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan. These structures allowed the water to stand and moisten the soil.
(v) Rooftop rainwater harvesting was commonly practised to store drinking water particularly in Rajasthan. In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer, almost all the houses traditionally had underground ‘tankas’ or ‘tanks’ for storing drinking water.
Q.5. What is rainwater harvesting? State the objectives of rainwater harvesting.
Ans. Rainwater harvesting is an efficient method of water conservation and management. The techniques of collecting and storing rainwater directly or recharging it into the ground through artificial means to improve groundwater storage is called rainwater harvesting. It includes traditional methods like (i) conversion of agricultural fields into rainfed storage structures locally known as ‘Khadins’ and ‘Johads’ in Rajasthan, (ii) rooftop rainwater harvesting to store drinking water in tanks or sumps for direct usage and to recharge and use groundwater for household purposes through abandoned wells or check dams, or through hand pumps during dry season.
Rainwater harvesting is very simple, practical and cost effective and can be easily conducted by individuals to solve their water problem.
The objectives of rainwater harvesting are :
(i) To prevent wastage and pollution of the monsoon rains.
(ii) To reduce runoff and control the flooding of roads.
(iii) To recharge and improve the quality of groundwater storage and raise water table.
(iv) The meet the demands of domestic water requirement during dry season.
(v) To solve problem of drinking water shortage especially in regions receiving less rainfall.