Ans) Shortage of water as compared to its demand is called as water scarcity. Its main reasons are as follows:-

1. The availability of water resources varies over space and time, mainly due to the variations in seasonal and annual precipitation.
2. Water scarcity in most cases is caused by over-exploitation, excessive use and unequal access to water among different social groups.
3. Water scarcity may be an outcome of a large and growing population and consequent greater demands for water, and unequal access to it.
4. The ever-increasing number of industries exerted pressure on existing freshwater resources.
5. In cities, pumping devices have been set up to meet the water needs, due to which water resources are being overexploited and have caused their depletion.

Ans)

1. Multipurpose projects and large dams have also been the cause of many new environmental movements like the ‘Narmada Bachao Andolan’ and the ‘Tehri Dam Andolan’.
2. Resistance to these projects has primarily been due to the large scale displacement of local communities. Local people often had to give up their land, livelihood, and their meagre access and control over resources for the greater good of the nation.
3. Irrigation has also changed the cropping pattern of many regions, with farmers shifting to water-intensive and commercial crops.
4. These projects have transformed the social landscape i.e., increasing the social gap between the richer land-owners and the landless poor. The dams did create conflicts between people wanting different uses and benefits from the same water resources. In Gujarat, the Sabarmati basin farmers were agitated and almost caused a riot over the higher priority given to water supply in urban areas.
5. Ironically, the dams that were built to control floods have triggered floods due to sedimentation in the reservoir. Moreover, the big dams have mostly been unsuccessful in controlling floods at the time of excessive rainfall.
6. The floods have not only devastated life and property but also caused extensive soil erosion.
7. Sedimentation also meant that the flood plains were deprived of silt, a natural fertiliser, further adding on to the problem of land degradation.
8. The multipurpose projects induced earthquakes, caused water-borne diseases and pests and pollution resulting from excessive use of water.

Ans) Methods of Rooftop Rainwater Harvesting are as follows:-

1. Rooftop rainwater is collected using a PVC pipe.
2. Water is filtered using sand and bricks.
3. The underground pipe takes water to the sump for immediate usage.
4. Water from the well recharges the underground water.
5. Take water from the well for later use.

Ans) Narmada Bachao Andolan:-

1. Narmada Bachao Andolan is a Non-Governmental Organisation (NGO) that mobilised tribal people, farmers, environmentalists, and human rights activists against the Sardar Sarovar dam being built across the Narmada river in Gujarat.
2. Initially, it focused on the environmental issues related to trees that would be submerged under the dam water. Recently, it has refocused its aim to enable displaced poor people to get full rehabilitation facilities from the government.
3. People felt that their suffering would not be in vain. They accepted the trauma of displacement, believing in the promise of irrigated fields and plentiful harvests.
4. Often, the survivors of Rihand told us that they accepted their sufferings as a sacrifice for the sake of their nation.
5. But now, after 30 bitter years of being a drift, their livelihood having even been more precarious, they keep asking: “Are we the only ones chosen to make sacrifices for the nation ?”

Ans) Rainwater harvesting in semi-arid regions of Rajasthan is carried out in the following ways:-

1. In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi, and Barmer, almost all the houses traditionally had underground tanks or tankas for storing drinking water.
2. The tankas could be as large as a big room; one household in Phalodi had a tank that was 6-1 m. deep, 4-27 m long and 2-44 m wide.
3. The tankas were part of the well-developed rooftop rainwater harvesting system and were built inside the main house or the courtyard. They were connected to the sloping roofs of the houses through a pipe.
4. Rain falling on the rooftops would travel down the pipe and was stored in these underground ‘tankas’. The first spell of rain was usually not collected as this would clean the roofs and the pipes. The rainwater from the subsequent showers was then collected.
5. The rainwater can be stored in the tankas till the next rainfall, making it an extremely reliable source of drinking water when all other sources are dried up, particularly in the summers. Rainwater or palar pani, as commonly referred to in these parts, is considered the purest form of natural water.
6. Many houses constructed underground rooms adjoining the ‘tanka’ to beat the summer heat as it would keep the room cool.
7. Presently in western Rajasthan, the practice of rooftop rainwater harvesting is on the decline as plenty of water is available due to the perennial Indira Gandhi Canal. Though some houses still maintain the tankas since they do not like the taste of tap water.

Ans) Modern adaptations of traditional rainwater harvesting methods are being carried out in the following ways to conserve and store water:-

1. In ancient India, along with the sophisticated hydraulic structures, there existed an extraordinary tradition of water harvesting systems.
2. People had in-depth knowledge of rainfall regimes and soil types and developed wide-ranging techniques to harvest rainwater, groundwater,river water, and flood water in keeping with the local ecological conditions and their water needs.
3. In hill and mountainous regions, people built diversion channels like the ‘guls’ or ‘kuls’ of the Western Himalayas for agriculture.
4. In western India, particularly in Rajasthan, rooftop rainwater harvesting was commonly practised to store drinking water.
5. In the flood plains of Bengal, people developed inundation channels to irrigate their fields.
6. In arid and semi-arid regions, agricultural fields were converted into rainfed storage structures that allowed the water to stand and moisten the soil like the ‘khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan.
7. In Gendathur village in Mysuru (Karnataka), villagers have installed, in their households’ rooftop, a rainwater harvesting system to meet their water needs. Nearly 200 households have installed this system, and the village has earned the rare distinction of being rich in rainwater.

Ans) A multi-purpose project is meant to those versatile projects that simultaneously serve more than one purpose. Multi-purpose projects have been started in India to bring revolutionary changes in Indian agriculture and industries. These are named as multi-purpose projects for their multiple uses. The following are the advantages-

1. These projects helped us in water storage, which we can use for irrigation, etc.
2. Multipurpose projects control floods.
3. The important benefit of this project is breeding fish in sufficient quantity, which is the source of income and solves the food problem as well.
4. These projects help in developing hydroelectric power is many ways. Electricity can be produced through dams by falling river water from canals constructed in the dams.

Major projects – (1) Bhakra-Nangal Project, (2) Indira Gandhi Canal Project, (3) Damodar River Valley Project, (4) Chambal Project.

Multi-purpose projects are better than traditional methods of irrigation – A multi-purpose project performs various functions, such as irrigation, control floods, electricity generation, and fish breeding etc. But ordinary irrigation plans implemented before independence were to do only one function that is irrigation and drainage fields. and thus are more beneficial. However, multi-purpose projects launched after Independence have various objectives