NCERT Solutions for Class 11 Geography - Drainage System

Q1: 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 Son
(c) The Kosi
(d) The Damodar
Ans: (d)

(ii) Which one of the following rivers has the largest river basin in India?
(a) The Indus
(b) The Brahmaputra
(c) The Ganga
(d) The Krishna
Ans: (c)

(iii) Which one of the following rivers is not included in ‘Panchnad’?
(a) The Ravi
(b) The Chenab
(c) The Indus
(d) The Jhelum
Ans: (c)

(iv) Which one of the following rivers flows in a rift valley?
(a) The Son
(b) The Narmada
(c) The Yamuna
(d) The Luni
Ans: (b)

(v) Which one of the following is the place of confluence of the Alaknanda and the Bhagirathi?
(a) Vishnu Prayag
(b) Rudra Prayag
(c) Karan Prayag
(d) Deva Prayag
Ans: (d)

Q2: State the differences between the following.
(i) River Basin and Watershed
Ans:

(ii) Dendritic and Trellis drainage pattern
Ans:

(iii) Radial and Centripetal drainage pattern
Ans:

(iv) Delta and Estuary
Ans:

Q3: Answer the following questions in about 30 words.
(i) What are the socio-economic advantages of inter-linking of rivers in India?
Ans: The socio-economic advantages of inter-linking of rivers in India are:

• The problems of floods and drought will get solved as excess water from an area can be transferred to water deficit areas.
• The inland waterway transportation will improve which will make the transportation of materials across the country easier.
• It will also help in imporving irrigational facilities which will increase the productivity.
• It will provide various opportunities such as hydro-electricity and fisheries activities.

(ii) Write three characteristics of the Peninsular river.
Ans: Three characteristics of the Peninsular river are:

• These rivers originate in Peninsular plateau and central highland.
• These are seasonal and dependent on monsoon rainfall.
• These rivers are smaller having fixed course with well adjusted valleys.

Q4: 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?
Ans: The important characteristic features of north Indian rivers are:

• They originate in Himalayan mountain covered with glaciers.
• These rivers are perennial in nature because they receive water from glacier and rainfall.
• These rivers form deep gorges and V-shaped valleys in mountainous areas.
• It has long course, flowing through the rugged mountains experiencing headward erosion and river capturing.
• These rivers are young and youthful, active and deepening in the valleys.

These are different from peninsular rivers because of these reasons:

• The north Indian rivers have very large basins while peninsular rivers have relatively smaller basin.
• The north Indian rivers are perennial as they receive water from glaciers and rainfall while peninsular rivers receive their water only from monsoon rains.
• The north Indian rivers are antecedent and consequent leading to dendritic pattern in plains while peninsular rivers are super imposed, rejuvenated resulting in trellis, radial and rectangular patterns.
• The north Indian rivers are young and youthful, active and deepening in the valleys while peninsular rivers are old with graded profile, and have almost reached their base levels.

(ii) Suppose you are travelling from Haridwar to Siliguri along the foothills of the Himalayas. Name the important rivers you will come across. Describe the characteristics of any one of them.
Ans: If we are travelling from Haridwar to Siliguri along the foothills of the Himalayas we will come across Gomti, Ramganga, Rapti, Gandak, Kosi, Kamla, Saryu, Sharda, Ghaghra, Mahanadi and Ganga.
The characteristics of Gandak:

• It rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest and drains the central part of Nepal
• It comprises two streams, namely Kaligandak and Trishulganga
• It enters the Ganga plain in Champaran district of Bihar and joins the Ganga at Sonpur near Patna.
• Its length is 630 Km.