SAI International School Grade-IX Geography (Module 11) Ch 3- Drainage Sub-topics Lesson Notes Introduction Drainage (Page no The term drainage refers to the river system of an area. 17) A river along with its tributaries and distributaries form a river system. The area drained by a single river system is called a drainage basin or a river basin. Any elevated area such as a mountain or an upland separating two adjoining drainage basins is known as water divide. The world’s largest river basin is of the Amazon River and the basin of River Ganga is India’s largest river basin. Drainage System in India( Page No!7,18) Drainage System in India The Indian rivers are divided into two major groups: the Himalayan rivers the Peninsular rivers Himalayan rivers The three major Himalayan rivers are the river Indus, the river Ganga and the river Brahmaputra. These are perennial rivers which mean they carry water throughout the year. They receive water from rain as well as from melted snow from the lofty mountains of Himalayas The Himalayan Rivers have long courses from their source to the sea and are joined by many large tributaries. They perform intensive erosional activities in their upper course and cut through the mountains making erosional features like waterfalls and gorges. The Himalayan rivers form meanders, oxbow lakes, floodplains and many other depositional features in their middle and lower courses. Peninsular rivers Most of the rivers of peninsular India originate in the Western Ghats and flow towards the Bay of Bengal. The major rivers are the Narmada, the Tapi, the Godavari, the Mahanadi, the Krishna and the Kaveri. They are seasonal and only rain-fed. The Peninsular rivers have shorter and shallower courses as compared to their Himalayan rivers. They are comparatively less erosive. Web Link https://www.youtube.com/watch?v=YaUCTQvSn_A https://www.youtube.com/watch?v=8a3r-cG8Wic Mind Map DRAINAGE Introduction River System Drainage Water Divide Drainage Basin Drainage Systems in India The Himalayan Rivers Work of a River The Peninsular Rivers Sl. No. 1. 2. 3. Assessment Worksheet The term drainage refers to (a) The mountain system of an area (b) The Climatic zone the area belongs to (c) The river system of an area (d) The types of forest of an area. Which of the following is not true? The main river collects its water from the: (a) small streams flowing from all the directions (b) catchment area or the catchment basin (c) snow melts in the high mountains. (d) Oceans and the seas What is the area drained by a single river system called? (a) Drainage basin (c) Drainage 4. 5. 6. 7. 8. 9. 10. (b) Water divide (d) Doab The area drained by a single river system is called: (a) a river system (c) a water divide (b) a river basin (d) the river course Any elevated area such as a mountain or an upland separating two adjoining drainage basins is known as: (a)a river system (c) a water divide (b) a river basin (d) the river course Which river has the largest river basin in the world? (Do You Know -pg. no-18) (a) River Nile (c) River Missourie and Mississippi (b) River Zambezi (d) River Amazon Which river has the largest basin in India? (Find out -pg. no-18), (NCERT ExerciseQ.N2,ii -pg. no-24) (a)River Brahmaputra (c) River Ganga (b)River Godavari (d) River Krishna The drainage system of India is mainly controlled by the (a) relief features of the subcontinent (b) temperature condition (c) forest Types (d) human activities Which of the following statement is true regarding Himalayan rivers? (a) They are only snow-fed (b) They are only rain-fed (c) They are both rain-fed and snow-fed. (d) They have broad and shallow valleys The rivers form meanders and ox-bow lakes in the (a) Upper course (c) catchment areas (b) middle and lower courses (d) u-shaped valleys Home Assignments Sl. No Sub Topic- Introduction, Drainage Systems in India 1. Marks (1/3/5) Pg No. 1 17 1 17 Between the two streams what is the marked upland called? Give one example of it. 2. 3. Identify the feature made by the river. In which course of the river is it found? In which course a river makes depositional features? Give one example of it. 1 18 1 18 What is the difference between tributary and the distributary? Write any three points. Discuss the significance difference between Himalayan and peninsular rivers. (NCERT Exercise- Q.N. 4 -pg. no-24) 3 18 5 17 Read the extract and answer the questions that follow: The two major Himalayan Rivers, 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. They perform intensive erosional activity in their upper courses and carry huge loads of silt and sand. In the middle and the lower courses, these rivers form meanders, oxbow lakes, and many other depositional features in their ﬂood plains. They also have well developed deltas. A large number of the Peninsular Rivers are seasonal, as their ﬂow 2+1+2= 5 17,1 8 4. Identify the feature A and the feature B made by the river. 5. 6. 7. is dependent on rainfall. During the dry season, even the large rivers have reduced ﬂow of water in their channels. The Peninsular Rivers have shorter and shallower courses as compared to their Himalayan counterparts. (i) Why do Himalayan Rivers perform intensive erosional activity? (ii) Which river makes largest delta of India as well as of world? (iii) How do the west ﬂowing peninsular rivers different from the east ﬂowing peninsular rivers?