Geography NCERT Chapter 3 PDF

DRAINAGE 3 T he term drainage describes the river DRAINAGE SYSTEMS IN INDIA system of an area. Look at the physical...

DRAINAGE 3 T he term drainage describes the river DRAINAGE SYSTEMS IN INDIA system of an area. Look at the physical The drainage systems of India are mainly map. You will notice that small streams controlled by the broad relief features of the flowing from different directions come together subcontinent. Accordingly, the Indian rivers to form the main river, which ultimately drains are divided into two major groups: into a large water body such as a lake or a sea the Himalayan rivers; and or an ocean. The area drained by a single river the Peninsular rivers. system is called a drainage basin. A closer Apart from originating from the two major observation on a map will indicate that any physiographic regions of India, the Himalayan elevated area, such as a mountain or an upland, and the Peninsular rivers are different from separates two drainage basins. Such an upland each other in many ways. Most of the is known as a water divide (Figure 3.1). Himalayan rivers are perennial. It means that they have water throughout the year. amm BB These rivers receive water from rain as well treea Sr S as from melted snow from the lofty ammA W at treea mountains. The two major Himalayan rivers, Sr S er Di vi de the Indus and the Brahmaputra originate from the north of the mountain ranges. They have cut through the mountains making gorges. The Himalayan rivers have long courses from their source to the sea. Figure 3.1 : Water Divide The world’s largest drainage basin is of the Amazon river Which river has the largest basin in India? Figure 3.2 : A Gorge Rationalised 2023-24 They perform intensive erosional activity in The Himalayan Rivers their upper courses and carry huge loads of The major Himalayan rivers are the Indus, the silt and sand. In the middle and the lower Ganga and the Brahmaputra. These rivers are courses, these rivers form meanders, oxbow long, and are joined by many large and lakes, and many other depositional features important tributaries. A river alongwith its in their floodplains. They also have well- developed deltas (Figure 3.3). tributaries may be called a river system. The Indus River System Source of River The river Indus rises in Tibet, near Lake Mansarowar. Flowing west, it enters India in the Upper Course Ladakh. It forms a picturesque gorge in this part. Several tributaries, the Zaskar, the Nubra, the Shyok and the Hunza, join it in the Kashmir Middle Course region. The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock. The Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan. Beyond this, the Indus Meander Ox-Bow Lake flows southwards eventually reaching the Arabian Sea, east of Karachi. The Indus plain Lower Course has a very gentle slope. With a total length of 2900 km, the Indus is one of the longest rivers of the world. A little over a third of the Indus basin is located in India Ladakh, Jammu and Delta Kashmir, Himachal Pradesh and Punjab and the rest is in Pakistan. Figure 3.3 : Some Features Made by Rivers A large number of the Peninsular rivers are According to the regulations seasonal, as their flow is dependent on rainfall. of the Indus Water Treaty (1960), India can During the dry season, even the large rivers use only 20 per cent of the total water carried by the Indus river system. This water is used for have reduced flow of water in their channels. irrigation in Punjab, Haryana and the southern The Peninsular rivers have shorter and and the western parts of Rajasthan. shallower courses as compared to their Himalayan counterparts. However, some of The Ganga River System them originate in the central highlands and flow The headwaters of the Ganga, called the towards the west. Can you identify two such ‘Bhagirathi’ is fed by the Gangotri Glacier and large rivers? Most of the rivers of peninsular joined by the Alaknanda at Devaprayag in India originate in the Western Ghats and flow Uttarakhand. At Haridwar, the Ganga emerges towards the Bay of Bengal. from the mountains on to the plains. 18 CONTEMPORARY INDIA-I Rationalised 2023-24  Figure 3.4 : Major Rivers and Lakes DRAINAGE 19 Rationalised 2023-24  the northernmost point of the Ganga delta. The river bifurcates here; the Bhagirathi-Hooghly (a distributary) flows southwards through the deltaic plains to the Bay of Bengal. The mainstream, flows southwards into Bangladesh and is joined by the Brahmaputra. Further downstream, it is known as the Meghna. This mighty river, with waters from the Ganga and the Brahmaputra, flows into the Bay of Bengal. The delta formed by these rivers is known as the Sundarban Delta. Figure 3.5 : Confluence of Bhagirathi and Alaknanda at Devaprayag The Sundarban Delta derived The Ganga is joined by many tributaries its name from the Sundari tree, which grows well from the Himalayas, a few of them being major in marshland. It is the world’s largest and fastest growing delta. rivers, such as the Yamuna, the Ghaghara, the It is also the home of Royal Bengal tiger. Gandak and the Kosi. The river Yamuna rises from the Yamunotri Glacier in the Himalayas. The length of the Ganga is over 2500 km. It flows parallel to the Ganga and as a right Look at Figure 3.4; can you identify the type of bank tributary meets the Ganga at Allahabad. drainage pattern formed by the Ganga river The Ghaghara, the Gandak and the Kosi rise system? Ambala is located on the water divide in the Nepal Himalaya. They are the rivers, between the Indus and the Ganga river systems. which flood parts of the northern plains every The plains from Ambala to the Sunderban year, causing widespread damage to life and stretch over nearly 1800 km, but the fall in its property, whereas, they enrich the soil for slope is hardly 300 metres. In other words, there agricultural use. is a fall of just one metre for every 6 km. The main tributaries, which come from the Therefore, the river develops large meanders. peninsular uplands, are the Chambal, the Betwa and the Son. These rise from semi-arid The Brahmaputra River System areas, have shorter courses and do not carry The Brahmaputra rises in Tibet east of much water in them. Find out where and how Mansarowar lake very close to the sources of they ultimately join the Ganga. the Indus and the Satluj. It is slightly longer than the Indus, and most of its course lies The Namami Gange Programme outside India. It flows eastwards parallel to is an Integrated Conservation Mission approved as the Himalayas. On reaching the Namcha a ‘flagship programme’ by the Union Government in June 2014 to accomplish the twin objectives of Barwa (7757 m), it takes a ‘U’ turn and enters effective abatement of pollution, conservation and India in Arunachal Pradesh through a gorge. rejuvenation of the national river, Ganga. You may explore about this project at http://nmcg.nic.in/ Here, it is called the Dihang and it is joined by NamamiGanga.sspx# the Dibang, the Lohit, and many other tributaries to form the Brahmaputra in Assam. Enlarged with the waters from its right and left bank tributaries, the Ganga flows Brahmaputra is known as eastwards till Farakka in West Bengal. This is the Tsang Po in Tibet and Jamuna in Bangladesh. 20 CONTEMPORARY INDIA-I Rationalised 2023-24  In Tibet, the river carries a smaller volume of water and less silt as it is a cold and a dry area. The Narmada river In India, it passes through a region of high conservation mission has been undertaken by the government of Madhya Pradesh by a scheme named rainfall. Here the river carries a large volume of Namami Devi Narmade. You may visit their website. water and considerable amount of silt. The http://www.namamidevinarmade.mp.gov.in to Brahmaputra has a braided channel in its entire learn more about it. length in Assam and forms many riverine islands. Do you remember the name of the world’s largest All tributaries of the Narmada are very short riverine island formed by the Brahmaputra? and most of these join the main stream at right Every year during the rainy season, the angles. The Narmada basin covers parts of river overflows its banks, causing widespread Madhya Pradesh and Gujarat. devastation due to floods in Assam and The Tapi Basin Bangladesh. Unlike other north Indian rivers, The Tapi rises in the Satpura ranges, in the the Brahmaputra is marked by huge deposits Betul district of Madhya Pradesh. It also flows of silt on its bed causing the riverbed to rise. in a rift valley parallel to the Narmada but it is The river also shifts its channel frequently. much shorter in length. Its basin covers parts of Madhya Pradesh, Gujarat and Maharashtra. The Peninsular Rivers The coastal plains between Western Ghats The main water divide in Peninsular India is and the Arabian Sea are very narrow. Hence, formed by the Western Ghats, which runs from the coastal rivers are short. The main west north to south close to the western coast. Most flowing rivers are Sabarmati, Mahi, of the major rivers of the Peninsula, such as Bharathpuzha and Periyar. Find out the states the Mahanadi, the Godavari, the Krishna and in which these rivers drain the water. the Kaveri flow eastwards and drain into the The Godavari Basin Bay of Bengal. These rivers make deltas at The Godavari is the largest Peninsular river. It their mouths. There are numerous small rises from the slopes of the Western Ghats in streams flowing west of the Western Ghats. the Nasik district of Maharashtra. Its length is The Narmada and the Tapi are the only long about 1500 km. It drains into the Bay of Bengal. rivers, which flow west and make esturies. The Its drainage basin is also the largest among the drainage basins of the peninsular rivers are peninsular rivers. The basin covers parts of comparatively smaller in size. Maharashtra (about 50 per cent of the basin area lies in Maharashtra), Madhya Pradesh, The Narmada Basin Odisha and Andhra Pradesh. The Godavari is The Narmada rises in the Amarkantak hills joined by a number of tributaries, such as the in Madhya Pradesh. It flows towards the west Purna, the Wardha, the Pranhita, the Manjra, in a rift valley formed due to faulting. On its the Wainganga and the Penganga. The last three way to the sea, the Narmada creates many tributaries are very large. Because of its length picturesque locations. The ‘Marble rocks’, and the area it covers, it is also known as the near Jabalpur, where the Narmada flows Dakshin Ganga. through a deep gorge, and the ‘Dhuadhar The Mahanadi Basin falls, where the river plunges over steep rocks, The Mahanadi rises in the highlands of are some of the notable ones. Chhattisgarh. It flows through Odisha to reach DRAINAGE 21 Rationalised 2023-24 the Bay of Bengal. The length of the river is Imagine that if Srinagar, Nainital and other about 860 km. Its drainage basin is shared by tourists places did not have a lake would they Maharashtra, Chhattisgarh, Jharkhand, have been as attractive as they are today? Have and Odisha. you ever tried to know the importance of lakes in making a place attractive to tourists? Apart The Krishna Basin from attraction for tourists, lakes are also useful Rising from a spring near Mahabaleshwar, the to human beings in many ways. Krishna flows for about 1400 km and reaches the Bay of Bengal. The Tungabhadra, the Lakes of large extent are called seas, Koyana, the Ghatprabha, the Musi and the like the Caspian, the Dead and the Aral seas. Bhima are some of its tributaries. Its drainage India has many lakes. These differ from basin is shared by Maharasthra, Karnataka each other in size and other characteristics. and Andhra Pradesh. Most lakes are permanent; some contain water The Kaveri Basin only during the rainy season, like the lakes in the basins of inland drainage of semi-arid The Kaveri rises in the Brahmagri range of the regions. There are some lakes which are the Western Ghats and it reaches the Bay of Bengal result of the action of glaciers and ice sheets, in south of Cuddalore in Tamil Nadu. The total while others have been formed by wind, river length of the river is about 760 km. Its main action and human activities. tributaries are Amravati, Bhavani, Hemavati A meandering river across a floodplain and Kabini. Its basin drains parts of Karnataka, forms cut-offs that later develops into ox-bow Kerala and Tamil Nadu. lakes. Spits and bars form lagoons in the coastal areas, e.g. the Chilika lake, the Pulicat The river Kaveri makes the lake and the Kolleru lake. Lakes in the region second biggest waterfall in India, known as of inland drainage are sometimes seasonal; for Shivasamudram Falls. The hydroelectric power example, the Sambhar lake in Rajasthan, which generated from the falls is supplied to Mysuru, Bengaluru and the Kolar Gold Field. is a salt water lake. Its water is used for producing salt. Most of the freshwater lakes are in the The name of the biggest waterfall Himalayan region. They are of glacial origin. in India. In other words, they formed when glaciers Besides these major rivers, there are some dug out a basin, which was later filled with smaller rivers flowing towards the east. The snowmelt. The Wular lake in Jammu and Damoder, the Brahmani, the Baitarni and the Kashmir, in contrast, is the result of tectonic Subarnrekha are some notable examples. activity. It is the largest freshwater lake in Locate them in your atlas. India. The Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important 71 per cent of the world’s freshwater lakes. surface is covered with water, but 97 per cent of that is salt water. Of the 3 per cent that is available as freshwater, three quarters of it is trapped as ice. LAKES You may be familiar with the valley of Kashmir and the famous Dal Lake, the house boats and shikaras, which attract thousands of tourists every year. Similarly, you may have visited some other tourist spot near a lake and enjoyed boating, swimming and other water games. Figure 3.6 : Loktak Lake 22 CONTEMPORARY INDIA-I Rationalised 2023-24  Apart from natural lakes, the damming of the rivers for the generation of hydel power has also led to the formation of lakes, such as Guru National River Conservation Plan Gobind Sagar (Bhakra Nangal Project). (NRCP) The river cleaning programme in the Activity country was initiated with the launching Make a list of natural and artificial of the Ganga Action Plan (GAP) lakes with the help of the atlas. in 1985. The Ganga Action Plan was expanded to cover other rivers under the Lakes are of great value to human beings. National River Conservation Plan A lake helps to regulate the flow of a river. (NRCP) in the year 1995. The objective During heavy rains, it prevents flooding and of the NRCP is to improve the water during the dry season, it helps to maintain quality of the rivers, which are major an even flow of water. Lakes can also be used water sources in the country, through for developing hydel power. They moderate the the implementation of pollultion climate of the surroundings; maintain the abatement work. Source: http://nrcd.nic.in/nrcp.pd as on aquatic ecosystem, enhance natural beauty, 25.07.17 help develop tourism and provide recreation. ROLE OF RIVERS IN THE ECONOMY Rivers have been of fundamental importance result, more and more water is being drained throughout the human history. Water from out of the rivers reducing their volume. On the rivers is a basic natural resource, essential other hand, a heavy load of untreated sewage for various human activities. Therefore, and industrial effluents are emptied into the riverbanks have attracted settlers from ancient rivers. This affects not only the quality of water times. These settlements have now become big but also the self-cleansing capacity of the river. cities. Make a list of cities in your state which For example, given the adequate streamflow, are located on the bank of a river. the Ganga water is able to dilute and assimilate Using rivers for irrigation, navigation, pollution loads within 20 km of large cities. hydro-power generation is of special But the increasing urbanisation and significance — particularly to a country like industrialisation do not allow it to happen and India, where agriculture is the major source the pollution level of many rivers has been of livelihood of the majority of its population. rising. Concern over rising pollution in our rivers led to the launching of various action plans to clean the rivers. Have you heard about RIVER POLLUTION such action plans? How does our health get The growing domestic, municipal, industrial affected by polluted river water? Think about and agricultural demand for water from rivers “life of human beings without fresh water”. naturally affects the quality of water. As a Arrange a debate on this topic in the class. EXERCISE 1. Choose the right answer from the four alternatives given below. (i) In which of the following states is the Wular lake located? (a) Rajasthan (c) Punjab (b) Uttar Pradesh (d) Jammu and Kashmir DRAINAGE 23 Rationalised 2023-24  (ii) The river Narmada has its source at (a) Satpura (c) Amarkantak (b) Brahmagiri (d) Slopes of the Western Ghats (iii) Which one of the following lakes is a salt water lake? (a) Sambhar (c) Wular (b) Dal (d) Gobind Sagar (iv) Which one of the following is the longest river of the Peninsular India? (a) Narmada (c) Godavari (b) Krishna (d) Mahanadi (v) Which one amongst the following rivers flows through a rift valley? (a) Mahanadi (c) Krishna (b) Tungabhadra (d) Tapi 2. Answer the following questions briefly. (i) What is meant by a water divide? Give an example. (ii) Which is the largest river basin in India? (iii) Where do the rivers Indus and Ganga have their origin? (iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga? (v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course? (vi) Which two Peninsular rivers flow through trough? (vii) State some economic benefits of rivers and lakes. 3. Below are given names of a few lakes of India. Group them under two categories – natural and created by human beings. (a) Wular (b) Dal (c) Nainital (d) Bhimtal (e) Gobind Sagar (f) Loktak (g) Barapani (h) Chilika (i) Sambhar (j) Rana Pratap Sagar (k) Nizam Sagar (l) Pulicat (m) Nagarjuna Sagar (n) Hirakund 4. Discuss the significant difference between the Himalayan and the Peninsular rivers. 5. Compare the east flowing and the west flowing rivers of the Peninsular plateau. 6. Why are rivers important for the country’s economy? Map Skills (i) On an outline map of India mark and label the following rivers: Ganga, Satluj, Damodar, Krishna, Narmada, Tapi, Mahanadi, and Brahmaputra. (ii) On an outline map of India mark and label the following lakes: Chilika, Sambhar, Wular, Pulicat, Kolleru. 24 CONTEMPORARY INDIA-I Rationalised 2023-24  Project/Activity Solve this crossword puzzle with the help of given clues. Across 1. Nagarjuna Sagar is a river valley project. Name the river? 2. The longest river of India. 3. The river which originates from a place known as Beas Kund. 4. The river which rises in the Betul district of MP and flows westwards. 5. The river which was known as the “Sorrow” of West Bengal. 6. The river on which the reservoir for Indira Gandhi Canal has been built. 7. The river whose source lies near Rohtang Pass. 8. The longest river of Peninsular India? Down 9. A tributary of Indus originating from Himachal Pradesh. 10. The river flowing through fault, drains into the Arabian Sea. 11. A river of south India, which receives rainwater both in summer and winter. 12. A river which flows through Ladakh, Gilgit and Pakistan. 13. An important river of the Indian desert. 14. The river which joins Chenab in Pakistan. 15. A river which rises at Yamunotri glacier. DRAINAGE 25 Rationalised 2023-24