NCERT Book Class 11 Geography Drainage System

DRAINAGE SYSTEM

You have observed water flowing through the rivers, nalas and even channels during rainy season which drain the excess water. Had these channels not been there, large-scale flooding would have occurred. Wherever channels are ill-defined or choked, flooding is a common phenomenon. Do you have a river near your village or city? Have you ever been there for boating or bathing? Is it perennial (always with water) or ephemeral (water during rainy season, and dry, otherwise)? 

Do you know that rivers flow in the same direction? You have studied about slopes in the other two textbooks of geography in this class . Can you, then, explain the reason for water flowing from one direction to the other? Why do the rivers originating from the Himalayas in the northern India and the Western Ghat in the southern India flow towards the east and discharge their waters in the Bay of Bengal? A river drains the water collected from a specific area, which is called its ‘catchment area’. An area drained by a river and its tributaries is called a drainage basin.

DRAINAGE SYSTEMS OF INDIA 

Indian drainage system consists of a large  number of small and big rivers. It is the outcome of the evolutionary process of the three major physiographic units and the nature and characteristics of precipitation

Exercise

1. Choose the right answer from the four alternatives given below.

(i) Which one of the following rivers was known as the ‘Sorrow of Bengal’?

     (a) The Gandak

     (b) The Kosi

     (c) The Son

     (d) The Damodar

(ii) Which one of the following rivers has the largest river basin in India?

     (a) The Indus

     (b) The Ganga

     (c) The Brahmaputra

     (d) The Krishna

(iii) Which one of the following rivers is not included in ‘Panchnad’?

     (a) The Ravi

     (b) The Indus

     (c) The Chenab

     (d) The Jhelum

(iv) Which one of the following rivers flows in a rift valley?

     (a) The Son

     (b) The Yamuna

     (c) The Narmada

     (d) The Luni

(v) Which one of the following is the place of confluence of the Alkananda and the Bhagirathi?

     (a) Vishnu Prayag

     (b) Karan Prayag

     (c) Rudra Prayag

     (d) Deva Prayag

2. State the differences between the following.

     (i) River Basin and Watershed

     (ii) Dendritic and Trellis drainage pattern

     (iii) Radial and Centripetal drainage pattern

     (iv) Delta and Estuary

3. Answer the following questions in about 30 words.

     (i) What are the socio-economic advantages of inter-linking of rivers in India?

     (ii) Write three characterstics of the Peninsular river.

4. Answer the following questions in not more than 125 words.

    (i) What are the important characteristic features of north Indian rivers? How are these different from Peninsular rivers?

    (ii) Suppose you are travelling from Hardwar to Siliguri along the foothills of the Himalayas. Name the important rivers you will come across. Describe the characteristics of any one of them.

Project/Activity

Study the Appendix III and answer the following questions.

  (i) Which river has the largest proportion of catchment area in the country?

  (ii) Make a comparative bar diagram on a graph paper to show the length of the courses of the rive

Please refer to attached file for NCERT Class 11 Geography Drainage System