OOS 2024-25 Grade 10 SST Geography Water Resources Notes PDF

GEOGRAPHY GRADE X CHAPTER 3: WATER RESOURCES ------------------------------------------------------------------------------------------------------------------------------- Only three-fourth of the earth’s surface is covered with water. Freshwater is mainly obta...

GEOGRAPHY GRADE X CHAPTER 3: WATER RESOURCES ------------------------------------------------------------------------------------------------------------------------------- Only three-fourth of the earth’s surface is covered with water. Freshwater is mainly obtained from surface run off and ground water that is continually being renewed and recharged through the hydrological cycle. All water moves within the hydrological cycle ensuring that water is a renewable resource. It is predicted that by 2025, nearly two billion people will live in absolute water scarcity. Water Scarcity: is a situation where countries and regions around the globe will suffer from non-availability of potable water to satisfy their basic needs and requirements. Availability of water resource varies over space and time, mainly due to the variations in seasonal and annual precipitation, and water scarcity in most cases is caused by over-exploitation, excessive use and unequal access to water among different social group. Reason for water scarcity – Quantitative and Qualitative aspects of water scarcity. QUANTITATIVE ASPECTS: 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 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. Most farmers have their own wells and tube-wells in their farms for irrigation to increase their produce. That it may lead to falling groundwater levels, adversely affecting water availability and food security of the people. Post-independent India witnessed intensive industrialisation and urbanization. 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. 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. 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. We find that fragile water resources are being over-exploited and have caused their depletion in several of these cities. Atal Bhujal Yojana (Atal Jal): is being implemented in 8220 water stressed Gram Panchayats of 229 administrative blocks/ talukas in 80 districts of seven states, viz. Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, and Uttar Pradesh. The selected States account for about 37 per cent of the total number of water— stressed (overexploited, critical and semi-critical) blocks in India.  One of the key aspects of Atal Jal is to bring in behavioural changes in the community, from the prevailing attitude of consumption to conservation and smart water management. QUALITATIVE ASPECTS- There is 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. Water may be polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in agriculture, thus, making it hazardous for human use. Jal Jeevan Mission (JJM): Government of India has accorded highest priority to improve the quality of life and enhance ease of living of people especially those living in rural 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 Need to conserve and manage our water resources. The need of the hour is to conserve and manage our water resources in order: To safeguard ourselves from health hazards, To ensure food security To continuation of our livelihoods and productive activities 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. Hydraulic Structures in Ancient India In the first century B.C., Sringaverapura near Allahabad had sophisticated water harvesting system channeling the flood water of the river Ganga. During the time of Chandragupta Maurya, dams, lakes and irrigation systems were extensively built. Evidences of sophisticated irrigation works have also been found in Kalinga, (Odisha), Nagarjunakonda (Andhra Pradesh), Bennur (Karnataka), Kolhapur (Maharashtra), etc. In the 11th Century, Bhopal Lake, one of the largest artificial lakes of its time was built. In the 14th Century, the tank in Hauz Khas, Delhi was constructed by Iltutmish for supplying water to Siri Fort area. MULTIPURPOSE RIVER VALLEY PROJECTS: Dams are referred to as multi - purpose projects where the many uses of the impounded water are integrated with one another. 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. Merits and demerits of multipurpose river valley project: MERITS: 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.  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 Sutluj-Beas river basin, the Bhakra – Nangal project water is being used both for hydel power production and irrigation. The Hirakud project in the Mahanadi basin integrates conservation of water with flood control. Multi-purpose projects, launched after Independence with their integrated water resources management approach, lead the nation to development and progress. 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. DEMERITS: multi-purpose projects and large dams have come under great scrutiny and opposition for a variety of reasons. Affects natural flow of running water: 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. They also fragment rivers making it difficult for aquatic fauna to migrate, especially for spawning. Affect natural vegetation and soil: The reservoirs that are created on the floodplains also submerge the existing vegetation and soil leading to its decomposition over a period of time. The flood plains are deprived of silt, a natural fertiliser, further adding on to the problem of land degradation. Creates conflicts and social movements and displacement of peopled: Multi-purpose projects and large dams have also been the cause of many new environmental movements like the ‘Narmada Bachao Andolan’ and the ‘Tehri Dam Andolan’ etc. 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. Failure to control flood: Ironically, the dams that were constructed 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. (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 slit, a natural fertilizer, further adding on to the problem of land degradation. Multi-purpose projects have induced earth quakes, cause water-borne diseases and pests and pollution resulting from excessive use of water. Change in cropping pattern: 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. It has transformed the social landscape i.e. increasing the social gap between the richer landowners and the landless poor. The dams did create conflicts between people wanting different uses and benefits from the same water resources. For eg. 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. Sardar Sarovar Dam: 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. Sardar Sarovar Project will provide irrigation facilities to 18.45 lakh hectare of land, covering 3112 villages in 15 districts of Gujarat. It will also irrigate 2,46,000 hectare of land in the strategic desert districts of Barmer and Jalore in Rajasthan and 37,500 hectare in the tribal hilly tract of Maharashtra through lift. About 75 per cent of the command area in Gujarat is drought prone while entire command in Rajasthan is drought prone. Assured water supply will soon make this area drought proof. RAINWATER HARVESTING: It is a technique of increasing the recharge of groundwater by capturing and storing rainwater by constructing structures such as dug wells, percolation pits, check dams, etc). The objectives of rainwater harvesting are: To meet the increasing demand for water. To reduce run off water. To avoid flooding of roads. To augment the groundwater storage and raise the water table. To reduce groundwater pollution. To improve the quality of groundwater To supplement domestic water requirement during summer and long dry spells. Traditional Water Harvesting system in India: In ancient India, along with the sophisticated hydraulic structures, there existed an extraordinary tradition of water-harvesting system. People had in-depth knowledgeof 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. In ancient India, along with the sophisticated hydraulic structures, there existed an extraordinary tradition of water-harvesting system In hill and mountainous regions, people built diversion channels like the ‘guls’ or ‘kuls’ of the Western Himalayas for agriculture. ‘Rooftop rain water harvesting was commonly practised to store drinking water, particularly in Rajasthan In the flood plains of Bengal, people developed inundation channels to irrigate their fields 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. Traditional rainwater harvesting carried out in the semi-arid regions of 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. 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. The tankas were part of the well-developed rooftop rainwater harvesting system. They 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 rainfall making it an extremely reliable source of drinking water when all other sources are dried up, particularly in the summers. Many houses constructed underground rooms adjoining the ‘tanka’ to beat the summer heat as it would keep the room cool. Bamboo drip irrigation system in Meghalaya: 200-year-old system of tapping stream and spring water by using bamboo pipes is common in Meghalaya. Bamboo pipes are used to divert perennial springs on the hilltops to the lower reaches by gravity. The channel sections, made of bamboo, divert water to the plant site where it is distributed into branches, again made and laid out with different forms of bamboo pipes. The flow of water into the pipes is controlled by manipulating the pipe positions. If the pipes pass a road, they are taken high above the land. Reduced channel sections and diversion units are used at the last stage of water application. The last channel section enables water to be dropped near the roots of the plant. Benefits/Advantages of Rain-water harvesting It increases water availability. Checks the declining water table. Is environmentally friendly. Improves the quality of groundwater. Prevents soul erosion and flooding. **************