Class 9 Geography Chapter 1 Question Answers - Contemporary India - I

Q1: Why are the Peninsular rivers seasonal in nature?
Ans: The Peninsular rivers are seasonal in nature because their flow is highly dependent on rainfall unlike the Himalayan rivers which are perennial. Most of the peninsular rivers flow through the plateaus and low hills devoid of snow. The peninsular rivers have shorter and shallower courses as compared to the Himalayan rivers. Such rivers fail to contain water for longer periods. When it rains good, they have ample water but when it is dry season, even the large rivers have reduced flow of water in their channels.

Q2: Give the features of the Himalayan rivers.
Ans: Most of the Himalayan rivers are perennial. It means that they have water throughout the year. 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 lower courses, these rivers form meanders, Ox-bow lakes and many other depositional features in their floodplain. They also have well-developed deltas.

Q3: Give some of the similarities between the Himalayan rivers and Peninsular rivers.
Ans: Although the Himalayan rivers differ from the Peninsular rivers in many ways, they have some similarities too:

• Both the river systems have their large drainage basins.
• Both make deltas at their mouths.
• The rivers of both the regions are joined by many tributaries as a result of which the main river gets ample water and silt.

Q4: Describe the following drainage patterns of streams:
(i) Radial
(ii) Dendrite
(iii) Trellis
(iv) Rectangular
Ans:

• Radial: The radial pattern develops when streams flow in different directions from a central peak or dome-like structure.
• Dendrite: The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.
• Trellis: A trellis drainage pattern develops where hard and soft rocks exist parallel to each other. A river joined by its tributaries, at approximately right angles, develops a trellis pattern.
• Rectangular: A rectangular drainage pattern develops on a strongly jointed rocky terrain.

Q5: Which three river systems form the Himalayan river system? Describe briefly any one of them.
Ans: The three river systems that form the Himalayan river system are:

• The Indus river system
• The Ganga river system
• The Brahmaputra river system
• The Brahmaputra rises in Tibet, east of Mansarovar lake very close to the sources of the Indus and the Satluj. Most of its course lies outside India. It flows eastwards parallel to the Himalayas. It enters India in Arunachal Pradesh through a gorge. Here, it is joined by several tributaries such as the Dibang, the Lohit to form the Brahmaputra in Assam. In the Indian part, the river passes through a region of high rainfall and therefore it carries a large volume of water and silt. It has a braided channel in its entire length in Assam and forms many riverine islands. Every year during the rainy season, the river overflows its banks, causing widespread devastation due to floods in Assam and Bangladesh.

Q6: Where does river Brahmaputra rise? Where does it enter into India? Name two of its tributaries.
Ans: River Brahmaputra rises in Tibet, east of Mansarovar lake very close to the sources of the Indus and the Satluj. It enters India in Arunachal Pradesh through a gorge. Two of its tributaries are—The Dibang and the Lohit.

Q7: What is the difference between tributary and distributary? Write any three points of distinction.
Ans:

• A tributary and a distributary are both bodies of freshwater that eventually meet with or diverge from rivers, but they differ in the direction that they flow.
• A tributary is a stream that flows into a larger river. A distributary is a stream that splits off from a larger river and flows in a different direction.
• A tributary increases the volume of water of the main river whereas a distributary decreases the volume of water of the main river. Example: the Yamuna is the tributary of the Ganga, whereas the Hooghly is the distributary of the Ganga.

Q8: Describe three important characteristics of Sundarbans Delta.
Ans:

• It is the world's largest and fastest-growing delta.
• It is also the home of Royal Bengal tigers.
• Sundarbans Delta derived its name from the Sundari tree which grows well in marshland.

Q9: Describe the three main features of the Narmada basin.
Ans:

• It flows towards the west in a rift valley formed due to faulting. On its way to the sea, the Narmada creates many picturesque locations.
• All the tributaries of the Narmada are very short and most of these join the main stream at right angles.
• The Narmada basin extends over states of Madhya Pradesh and Gujarat. It is bounded by the Vindhyas on the north, by the Maikala range on the east, by the Satpuras on the south and by the Arabian Sea on the west.

Q10: Define drainage basin and describe two patterns of drainage in India.
Ans:

• Drainage basin: The area drained by a single river system is called a drainage basin.
• Radial: The radial pattern develops when streams flow in different directions from a central peak or dome-like structure.
• Dendritic: The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.

Q11: Where does the river Narmada originate? Name any two picturesque locations formed by it.
Ans: The Narmada rises in the Amarkantak hills in Madhya Pradesh. It flows towards the west in a rift valley formed due to faulting. The 'Marble rocks' near Jabalpur where the Narmada flows through a deep gorge, and the 'Dhuadhar falls' where the river plunges over steep rocks, are some of notable picturesque locations.

Q12: Where does the river Indus rise from? What is its length? Write any two tributaries of river Indus.
Ans: The river Indus rises in Tibet, near lake Mansarovar, flowing west, it enters India in the Ladakh district of Jammu and Kashmir. The total length of the river is 2900 km. Two tributaries of the Indus are – the Zaskar and the Nubra.

Q13: Where does the river Tapi originate? Write its main features.
Ans:

• The Tapi is one of the major peninsular rivers which rises in the Satpura ranges, in the Betul district of Madhya Pradesh. The main features of this river basin are given below:
• It flows in a rift valley parallel to the Narmada but it is much shorter in length. Its basin covers parts of Madhya Pradesh, Gujarat, and Maharashtra.
• It has two well-defined physical regions, i.e., the hilly regions and the plains. The hilly regions are well-forested while the plains are broad and fertile areas suitable for cultivation.

Q14: Describe important features of the Mahanadi basin. Give three factual pieces of information about the Mahanadi basin.
Ans: The Mahanadi is one of the major peninsular rivers which rise in the highlands of Chhattisgarh. It flows through Odisha to reach the Bay of Bengal. The total length of the river is about 860 km. Its drainage basin is shared by Maharashtra, Chhattisgarh, Jharkhand, and Odisha.

Q15: Where does the river Kaveri originate? What is its total length? Name its main tributaries.
Ans: The Kaveri rises in the Brahmagri range of the Western Ghats and it reaches the Bay of Bengal in the south of Cuddalore, in Tamil Nadu. The total length of the river is about 760 km. The main tributaries of this river are—Amravati, Bhavani, Hemavati, and Kabini. Its basin drains parts of Karnataka, Kerala, and Tamil Nadu.

Q16: Describe important features of the Krishna basin.
Ans: The Krishna is an important peninsular river. It rises from a spring near Mahabaleshwar and flows for about 1400 km and drains into the Bay of Bengal. The Tungabhadra, the Koyana, the Ghatprabha, the Musi, and the Bhima are some of its tributaries. Its drainage basin is shared by Maharashtra, Karnataka, and Andhra Pradesh.

Q17: Which two peninsular rivers form estuaries? Name the states in which these rivers drain the water.
Ans: The two peninsular rivers that form estuaries are the Narmada and the Tapi. The Narmada drains into Madhya Pradesh and Gujarat. The Tapi drains into Madhya Pradesh, Gujarat, and Maharashtra.

Q18: Why do the Himalayan rivers get flooded every year? Mention the main advantages of these rivers.
Ans: The Himalayan rivers are perennial having water throughout the year. These rivers receive water from melted snow from the lofty mountains. They also receive abundant water from rainfall during the rainy season. So, they get flooded every year. The Himalayan rivers have great advantages:

• They have longer courses and they carry more sediments in them enriching the soil of the northern plains for extensive agriculture.
• They have great potential for hydro power making irrigation and navigation easy.

Q19: Why are the peninsular rivers not navigable?
Ans: The Peninsular rivers are mostly seasonal in nature. The flow of these rivers depends upon rainfall and they usually get dried up in the summer. River beds are uneven, rocky, and have sharp slopes. Dams cannot be constructed on these rivers. These reasons make peninsular rivers not navigable.

Q20: Give a brief description of freshwater lakes found in India.
Ans: Most of the freshwater lakes are located in the Himalayan regions. They are of glacial origin. They formed when glaciers dug out a basin, which was later filled with snowmelt. The Wular lake in Jammu and Kashmir is the largest freshwater lake in India. It is the result of tectonic activity. The Dal lake, Bhimtal, Nainital, Loktak, and Barapani are some other important freshwater lakes in our country.

Q21: Describe how the lakes found in India differ from each other in size, and other characteristics.
Ans:
There are many lakes in India. These differ from each other in size, and other characteristics:

• Most lakes are permanent while some contain water only during the rainy season, like the lakes in the basins of inland drainage of semi-arid regions.
• Some lakes are the result of the action of glaciers and ice-sheets; while the others have been formed by wind, river action, and human activities.
• A meandering river across a floodplain forms cut-offs that later develop into Ox-box lakes.

Q22: Which is the largest peninsular river? Describe some of its important features.
Ans:
The Godavari is the largest peninsular river. Some of its important features are:

• It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra. Its length is about 1500 km.
• It drains into the Bay of Bengal. Its drainage basin also the largest among the peninsular rivers.
• The basin covers parts of Maharashtra, Madhya Pradesh, Odisha and Andhra Pradesh.
• The Godavari is joined by a number of tributaries such as the Puma, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga. The last three tributaries are very large.
• The Godavari river is also known as the ‘Dakshin Ganga’ since it is largest Peninsular river like the large Himalayan river. It is like the Ganga river in the south so it is also called he ‘Dakshin Ganga’.

Q23: Describe the important characteristics of the Brahmaputra river system.
Ans:
The three river systems that form the Himalayan river system are:

• The Indus river system
• The Ganga river system
• The Brahmaputra river system

The Brahmaputra rises in the Tibet, east of Mansarovar lake very close to the sources of the Indus and the Satluj. Most of its course lies outside India. It flows eastwards parallel to the Himalayas. It enters India in Arunachal Pradesh through a gorge. Here, it is joined by several tributaries such as the Dibang, the Lohit to form the Brahmaputra in Assam.
In Indian part, the river passes through a region of high rainfall and therefore it carries a large volume of water and silt. It has a branded channel in its entire length in Assam and forms many riverine islands. Every year during the rainy season, the river overflows its banks, causing widespread devastation due to floods in Assam and Bangladesh.

Q24: Give the main features of the Ganga river system.
Ans:
The Ganga river system consists of the master river Ganga and a large number of its tributaries such as the Yamuna, the Ghaghara, the Gandak and the Kosi. The main features of this river system are:

• This system drains a very large area comprising the middle part of the Himalayas in the north, the northern part of the India plateau in the south and the Ganga plain in between Needless to say that the Ganga plain is one of the most fertile plains of the world.
• The Ganga originates as Bhagirathi from the Gangotri glacier in Uttar Kashi district of Uttarakhand at an elevation of 7,010 m. Alaknanda joins it at Devaprayag.
• After travelling 280 km from its source, the Ganga reaches Haridwar, debouches from the hills and enters plain area. From here it flows in south and south-east direction for a distance of 770 km to reach Allahabad. Here it is joined by the Yamuna which is the main tributary.
• Enlarged with the waters from its right and left bank tributaries, The Ganga flows eastwards till Farakka in West Bengal. Subsequently, It flows southwards into Bangladesh and is joined by the Brahmaputra. Further down stream, it is known as the Meghna. This mighty river, with waters from the Ganga and the Brahmaputra, flows into the Bay of Bengal.
•  The length of the Ganga is over 2500 km. Its basis is the most heavily populated in the world with over 400 million people living here.

Q25: Which are the major Himalayan rivers? Give a brief description of the Indus river system.
Ans:

• The major Himalayan rivers are the Indus, the Ganga and the Brahmaputra. The Indus river is one of the beautiful rivers of India. Together with its tributaries such as the Satluj, the Beas, the Ravi, the Chenab and the Jhelum, the Indus river forms an important river system, which helps in the development of Indian economy.
• The river Indus originates near the Mansarovar lake in the Tibetan plateau, on the northern slopes of the Kailash mountain range. Flowing west, it enters India in the Ladakh district of Jammu and Kashmir. Subsequently, the river gets into Pakistan through Balistan and Gilgit, running across the north in a southward route down the entire span of Pakistan, to join the Arabian Sea, east of Karachi, The Indus plain has a very gentle slope.
• The total length of the river is 2900 km. It is also the longest river in Pakistan. A little over a third of the Indus basin is located in India in the states of Jammu and Kashmir, Himachal Pradesh and the Punjab and the rest is in Pakistan.