Water Resources - NCERT Class 10 PDF

9 Water Resources "Water is an indispensable...

9 Water Resources "Water is an indispensable gift of nature. No life on earth is possible without water. Water has no alternative. Our country faces problems due to it's monsoonal regime of rainfall. Hence various ways must be employed to save this gift of nature" Introduction Freshwater can be obtained directly from precipitation, surface run off and groundwater that is continuously being renewed and recharged through the hydrological cycle. All water moves within the hydrological cycle ensuring that water is a renewable resource. We know that the three-fourth of the world is covered with water and water is a renewable resource, then how is it that countries and regions around the globe suffer from water scarcity? Why is it predicted that by 2025, nearly two billion people will live in absolute water scarcity? Water Scarcity and the Need for Water Conservation and Management When we speak of water shortages, we immediately associate it with regions having low rainfall or those that are drought prone. We instantaneously visualise the deserts of Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science Rajasthan and women balancing many ‘matkas’ (earthen pots) used for collecting and storing water and travelling long distances to get water. True, the availability of water resources varies over space and time, mainly due to the variations in seasonal and annual precipitation, but water scarcity in most cases is caused by over- exploitation, excessive use and unequal access to water among different social groups. Many of our cities are such examples. Thus, water scarcity may be an outcome of large and growing population and consequent greater demands for water, and unequal access to it. A large population requires more water not only for domestic use but also to produce more NCERT Basics : Class 10 food. Hence, to facilitate higher food-grain production, water resources are being over- exploited to expand irrigated areas for dry-season agriculture. Irrigated agriculture is the largest consumer of water. Now it is needed to revolutionise the agriculture through developing drought resistant crops and dry farming techniques. You may have seen in many television advertisements that most farmers have their own wells and tube-wells in their farms for irrigation to increase their produce. But have you ever wondered what this could result in? That it may lead to falling groundwater levels, adversely affecting water availability and food security of the people. On one hand Israel gets annual rainfall of 25 cm still there is no shortage of water in that country whereas with an average annual rainfall of 114 cm in our country we saw, drought occurs in some part every year. Due to lack of proper water management as per the availability and nature of water in the country, the rainwater rapidly flows into the rivers and drains and goes into the sea due to which there is water shortage for the country for about nine months after the rains. These are the basic reasons for water scarcity in our country, which we can overcome only through proper management. Post-independent India witnessed intensive industrialisation and urbanisation, creating vast opportunities for us. Today, large industrial houses are as commonplace as the industrial units of many MNCs (Multinational Corporations). The ever- increasing number of industries has made matters worse by exerting pressure on existing freshwater resources. Industries, apart from being heavy users of water, also require power to run them. Much of this energy comes from hydroelectric power. Today, in India hydroelectric power contributes approximately 22 per cent of the total electricity produced. Moreover, multiplying urban centres with large and dense populations and urban lifestyles have not only added to water and energy requirements but have further aggravated the problem. If you look into the housing societies or colonies in the cities, you would find that most of these have their own groundwater pumping devices to meet their water needs. Not Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science surprisingly, we find that fragile water resources are being over- exploited and have caused their depletion in several of these cities. So far, we have focused on the quantitative aspects of water scarcity. Now, let us consider another situation where water is sufficiently available to meet the needs of the people, but, the area still suffers from water scarcity. This scarcity may be due to bad quality of water. Lately, there has been a growing concern that even if there is ample water to meet the needs of the people, much of it may be polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in agriculture, thus, making it hazardous for human use.  Social Science Government of India has accorded highest priority to improve the quality of life and enhance ease of living of people especially those living in rual areas by announcing the Jal Jeevan Mission (JJM). The Goal of JJM is to enable every rural household get assured supply of potable piped water at a service level of 55 litres per capita per day regularly on long-term basis by ensuring functionality of the tap water connections. India’s rivers, especially the smaller ones, have all turned into toxic streams. And even the big ones like the Ganga and Yamuna are far from being pure. The assault on India’s rivers – from population growth, agricultural modernisation, urbanisation and industrialisation – is enormous and growing by the day….. This entire life stands threatened. Need to Conserve and Manage Our Water Resources The need of the hour is to conserve and manage our water resources, to safeguard ourselves from health hazards, to ensure food security, continuation of our livelihoods and productive activities and also to prevent degradation of our natural ecosystems. Over exploitation and mismanagement of water resources will impoverish this resource and cause ecological crisis that may have profound impact on our lives. Multi-Purpose River Projects and Integrated Water Resources Management Archaeological and historical records show that from ancient times we have been constructing sophisticated hydraulic structures like dams built of stone rubble, reservoirs or lakes, embankments and canals for irrigation. Hydraulic Structures in Ancient India (i) In the first century B.C., Sringaverapura near Allahabad had sophisticated water harvesting system channelling the flood water of the river Ganga. (ii) During the time of Chandragupta Maurya, dams, lakes and irrigation systems were extensively built. (iii) Evidence of sophisticated irrigation works have also been found in Kalinga, (Odisha), Nagarjuna konda (Andhra Pradesh), Bennur (Karnataka), Kolhapur (Maharashtra), Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science etc. (iv) In the 11th Century, Bhopal Lake, one of the largest artificial lakes of its time was built. (v) In the 14th Century, the tank in Hauz Khas, Delhi was constructed by Iltutmish for supplying water to Siri Fort area. What are dams and how do they help us in conserving and managing water? Dams were traditionally built to impound rivers and rainwater that could be used later to irrigate agricultural fields. Today, dams are built not just for irrigation but for electricity generation, water supply for domestic and industrial uses, flood control, recreation, inland navigation and fish breeding. NCERT Basics : Class 10 Hence, dams are now referred to as multi- purpose projects where the many uses of the impounded water are integrated with one another. For example, in the Sutlej- Beas River basin, the Bhakra - Nangal project water is being used both for hydel power production and irrigation. Similarly, the Hirakud project in the Mahanadi basin integrates conservation of water with flood control. Hirakud Dam A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. “Dam” refers to the reservoir rather than the structure. Most dams have a section called a spillway or weir over which or through which it is intended that water will flow either intermittently or continuously. Dams are classified according to structure, intended purpose or height. Based on structure and the materials used, dams are classified as timber dams, embankment dams or masonry dams, with several subtypes. According to the height, dams can be categorised as large dams and major dams or alternatively as low dams, medium height dams and high dams. Multi-Purpose Projects - 'Temples of Modern India' Multi-purpose projects, launched after Independence with their integrated water resources management approach, were thought of as the vehicle that would lead the nation to development and progress, overcoming the handicap of its colonial past. Jawaharlal Nehru proudly proclaimed the dams as the 'temples of modern India'; the reason being that it would integrate development of agriculture and the village economy with rapid industrialisation and growth of the urban economy. In recent years multi-purpose projects and large dams have come under great scrutiny and opposition for a variety of reasons- Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science (i) Regulating and damming of rivers affect their natural flow causing poor sediment flow and excessive sedimentation at the bottom of the reservoir, resulting in rockier stream beds and poorer habitats for the rivers' aquatic life. (ii) Dams also fragment rivers making it difficult for aquatic fauna to migrate, especially for spawning. (iii) The reservoirs that are created on the floodplains submerge the existing vegetation and soil leading to its decomposition over a period of time. (iv) Dams have also been the cause of many new social movements like the 'Narmada Bachao Andolan' and the 'Tehri Dam Andolan' etc.  Social Science (v) 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. (vi) Irrigation has also changed the cropping pattern of many regions with farmers shifting to water intensive and commercial crops. This has great ecological consequences like salinisation of the soil. Sardar Sarovar Dam has been built over the Narmada River in Gujarat. This is one of the largest water resource projects of India covering four states—Maharashtra, Madhya Pradesh, Gujarat and Rajasthan. The Sardar Sarovar project would meet the requirement of water in drought-prone and desert areas of Gujarat (9,490 villages and 173 towns) and Rajasthan (124 villages) Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science Major rivers and dams NCERT Basics : Class 10 (i) It has transformed the social landscape i.e., increasing the social gap between the richer landowners and the landless poor. (ii) Inter-state water disputes are also becoming common with regard to sharing the costs and benefits of the multi-purpose project. (iii) In Gujarat, the Sabarmati-basin farmers were agitated and almost caused a riot over the higher priority given to water supply in urban areas, particularly during droughts. Inter-state water disputes are also becoming common with regard to sharing the costs and benefits of the multi-purpose project. Major River Projects River Projects Rivers Salal Project Chenab Bhakra Nangal Sutlej Tehri Bhagirathi (Ganga) Narora Ganga Gandhi Sagar Chambal Rana Pratap Sagar Chambal Sardar Sarovar Narmada Pravara Paravara Godavari) Koyna Krishna Nagarjuna Sagar Krishna Tungabhadra Tungabhadra (Krishna) Mettur Kaveri Krishna Raj Sagar Kaveri Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science Periyar Kaveri Hirakud Mahanadi Tilay, Konar, Maithon and Panchet Damodar (D.V.C.) Objections to the projects Most of the objections to the projects arose due to their failure to achieve the purposes for which they were built. Ironically, the dams that were constructed to control floods have triggered floods due to sedimentation in the reservoir.  Social Science Narmada Bachao Andolan or Save Narmada Movement 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. It originally focused on the environmental issues related to trees that would be submerged under the dam water. Recently it has re-focused the aim to enable poor citizens, especially the ousted (displaced people) to get full rehabilitation facilities from the government. Moreover, the big dams have mostly been unsuccessful in controlling floods at the time of excessive rainfall. You may have seen or read how the release of water from dams during heavy rains aggravated the flood situation in Maharashtra and Gujarat in 2006. The floods have not only devastated life and property but also caused extensive soil erosion. Sedimentation also meant that the flood plains were deprived of silt, a natural fertiliser, further adding on to the problem of land degradation. It was also observed that the multi-purpose projects induced earthquakes, caused water- borne diseases and pests and pollution resulting from excessive use of water. The Krishna-Godavari dispute is due to the objections raised by Karnataka and Andhra Pradesh governments? It is regarding the diversion of more water at Koyna by the Maharashtra government for a multipurpose project. This would reduce downstream flow in their states with adverse consequences for agriculture and industry. 1 1. Match the columns Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science Column I Column II (A) Tehri (i) Ganga (B) Koyna (ii) Chambal (C) Mettur (iii) Krishna (D) Narora (iv) Bhagirathi (Ganga) (E) Gandhi Sagar (v) Kaveri NCERT Basics : Class 10 Rainwater harvesting Water harvesting system, a viable alternative, both socio-economically and environmentally. (a) Water-harvesting system in ancient India People had in-depth knowledge of rainfall regimes and soil types and developed wide ranging techniques to harvest rainwater, groundwater, river water and flood water in keeping with the local ecological conditions and their water needs. (i) In hill and mountainous regions, people-built diversion channels like the 'guls' or 'kuls' of the Western Himalayas for agriculture. (ii) 'Rooftop rainwater harvesting' was commonly practised to store drinking water, particularly in Rajasthan. (iii) In the flood plains of Bengal, people developed inundation channels to irrigate their fields. (iv) In arid and semi-arid regions, agricultural fields were converted into rain fed storage structures that allowed the water to stand and moisten the soil like the 'Khadins' in Jaisalmer and 'Johads' in other parts of Rajasthan. (b) Rooftop rainwater harvesting as practised in Rajasthan In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer, almost all the houses traditionally had underground tanks or tankas for storing drinking water. The tanks could be as large as a big room; one household in Phalodi had a tank that was 6.1 metres deep, 4.27 metres long and 2.44 metres wide. Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science (a)Recharge through (b) Recharge through Hand Pump Abandoned Dug well Rooftop rainwater is collected using a PVC pipe Filtered using sand and bricks Underground pipe takes water to sump for immediate usage Excess water from the sump is taken to the well Water from the well recharges the underground Take water from the well (later) Rooftop Rainwater Harvesting  Social Science 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. 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. The rainwater can be stored in the tankas till the next A kul is a channel rainfall making it an extremely reliable source of drinking built by people in the hilly regions which water when all other sources are dried up, particularly in leads to a circular the summers. Rainwater, or palar pani, as commonly village tank, from which water is referred to in these parts, is considered the purest form released as and when of natural water. Many houses constructed underground required. rooms adjoining the ‘tanka’ to beat the summer heat as it would keep the room cool. Rooftop rainwater harvesting is the most common practice in Shillong, Meghalaya. It is interesting because Cherapunjee and Mawsynram situated at a distance of 55 km. from Shillong receive the highest rainfall in the world, yet the state capital Shillong faces acute shortage of water. Nearly every household in the city has a rooftop rainwater harvesting structure. Nearly 15-25 per cent of the total water requirement of the household comes from rooftop water harvesting. Today, in western Rajasthan, sadly 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. Rooftop harvesting was common across the towns and villages of the Thar. Rainwater that falls on the sloping roofs of houses is taken Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science through a pipe into an underground tanka (circular holes in the ground). built in the main house or in the courtyard. The picture above shows water being taken from a neighbour’s roof through a long pipe. Here the neighbours’ rooftop has been used for collection of rainwater. The picture shows a hole through which rainwater flows down into an underground tanka. NCERT Basics : Class 10 Modern adaptations of traditional Rainwater harvesting methods In many parts of rural and urban India, rooftop rainwater harvesting is being successfully adapted to store and conserve water. In Gendathur, a remote backward village Tamil Nadu is the first state in India in Mysore, Karnataka, villagers have installed, in their which has made household's rooftop, rainwater harvesting system to rooftop rainwater meet their water needs. Nearly 200 households have harvesting structure compulsory to all the installed this system and the village has earned the rare houses across the state. distinction of being rich in rainwater. Gendathur receives an annual precipitation of 1,000 mm, and with 80 per cent of collection efficiency and of about 10 fillings, every house can collect and use about 50,000 litres of water annually. From the 20 houses, the net amount of rainwater harvested annually amounts to 1,00,000 litres. In Meghalaya, a 200-year-old system of tapping stream and spring water by using bamboo pipes, is prevalent. About 18-20 litres of water enters the bamboo pipe system, gets transported over hundreds of metres, and finally reduces to 20-80 drops per minute at the site of the plant. 1 1. (A) – (iv), (B) – (iii), (C) – (v), (D) – (i), (E) – (ii) Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science  Social Science MIND MAP 96.5 % total volume of water 4%Global Precipitation Availability 2.5% Fresh water 2025-Absoulte Water Scarcity of Water Water Quantitively Qualitative Scarcity Dam Hydraulic Reservoir Stone Rubble Embankment structure Kalinga (Odisha) Bennur (Karnataka) Hydraulic structure Nagarjunkonda Kolaphur in Ancient India (Andhra Pradesh) (Maharashtra) Water Resource s Advantage Disadvantage Irrigation facilities Sedimentation of river Multi – Purpose Navigation bottom Project Hydro electricity Spoil marine life habitat Flood Control Earthquake Fish breeding Water borne diseases Interstate water dispute Flood Rooftop Tankas Traditional method Khadin Kulis of water harvesting Inundatio Bamboo drip irrigation n Publishing$\PNCF\2024-25\LIVE Module\SET-1\NCERT\10th\Social Science