Geography of Assam — Question Answer
Welcome to HSLC Guru. This post provides complete ASSEB Class 9 Social Science Geography Chapter 4 solutions for Geography of Assam.
সাৰাংশ: অসম ভাৰতৰ উত্তৰ-পূব অঞ্চলত অৱস্থিত এখন ৰাজ্য। এই অধ্যায়ত অসমৰ ভূ-প্ৰাকৃতিক বিভাজন — ব্ৰহ্মপুত্ৰ উপত্যকা, বৰাক উপত্যকা, কাৰ্বি মালভূমি আৰু বৰাইল শ্ৰেণী তথা দক্ষিণৰ পাহাৰসমূহৰ বিষয়ে আলোচনা কৰা হৈছে। ইয়াৰ উপৰি অসমৰ জলবায়ু, বৰষুণ, মাটিৰ প্ৰকাৰ, অৰণ্য, ৰাষ্ট্ৰীয় উদ্যান আৰু প্ৰশাসনিক বিভাজন আদিৰ বিষয়েও কোৱা হৈছে। অসমৰ জলবায়ু উপ-ক্ৰান্তীয় মৌচুমী প্ৰকৃতিৰ, য’ত গ্ৰীষ্মকালত অধিক বৰষুণ হয়। ৭৮,৪৩৮ বৰ্গ কিলোমিটাৰ মাটিকালিৰ এই ৰাজ্যখনৰ ৰাজধানী দিছপুৰ।
Summary: Assam is a state located in the north-eastern region of India. This chapter discusses the physiographic divisions of Assam — the Brahmaputra Valley, the Barak Valley, the Karbi Plateau and the Barail range with the southern hills. It also covers the climate, rainfall, soil types, forests, national parks and administrative divisions of the state. Assam has a sub-tropical monsoon climate marked by heavy summer rainfall. With a total land area of 78,438 sq km, its capital is Dispur.
Textbook Questions and Answers
Very Short Answer
1. Write four names each of the north-bank and south-bank tributaries of the Brahmaputra river.
Answer: North-bank tributaries: Subansiri, Ranganadi, Buroi and Jia Bharali. South-bank tributaries: Burhi Dihing, Disang, Dikhow and Jhanzi.
2. What is the main reason behind the occurrence of rainfall in Assam during the summer season?
Answer: Summer rainfall in Assam occurs mainly due to the orographic and cyclonic processes of the moisture-laden south-west monsoon wind.
3. Write the names of the places in Assam witnessing the highest and lowest rainfall, along with the amount of rainfall.
Answer: North Lakhimpur witnesses the highest annual rainfall of about 335 cm, while Lamding witnesses the lowest annual rainfall of about 129 cm.
4. State the location and land area of Kaziranga National Park.
Answer: Kaziranga National Park is spread over the Golaghat, Nagaon and Sonitpur districts of Assam and covers a total area of about 858.98 sq km. It is world-famous for the one-horned rhinoceros.
5. What is the land area of Assam? Where is the state’s capital located? Write the names of the largest and smallest districts of Assam in respect of land area.
Answer: The total land area of Assam is 78,438 sq km. The capital of the state is located at Dispur (near Guwahati). In terms of land area, the largest district is Karbi Anglong (about 10,434 sq km) and the smallest district is Kamrup Metropolitan (about 955 sq km).
6. What is the population of Assam according to the 2011 census? Write the names of the largest and smallest districts of Assam in terms of population size.
Answer: According to the 2011 census, the population of Assam is about 3.12 crore (3,11,69,272). In terms of population, the largest district is Nagaon (about 28,23,768) and the smallest district is Dima Hasao (about 2,14,102).
Short Answer
7. What are the physiographic divisions of Assam?
Answer: On the basis of physiography, Assam can be divided mainly into four regions — (a) the Brahmaputra Valley, (b) the Barak Valley, (c) the Karbi Plateau and (d) the Barail range and the southern hills.
8. What are the physiographic regions of the Brahmaputra Valley?
Answer: The Brahmaputra Valley can be divided from north to south into four physiographic units — (a) the northern foothills, (b) the north and south bank plains, (c) the floodplains with char lands, and (d) the southern foothills.
9. Give a brief description of the Brahmaputra plain region.
Answer: The Brahmaputra plain has been formed by the deposition of a large amount of alluvium carried by the Brahmaputra river and its tributaries. The north-bank plain has an average width of about 30 km in the lower part and about 10 km in the upper part, whereas the south-bank plain is comparatively narrow (about 5 km). Because of its fertile alluvial soil, the region is highly suitable for agriculture.
10. Give a brief description of the floodplain region of the Brahmaputra.
Answer: The area lying between the north and south bank plains, where floods occur frequently due to the Brahmaputra river, is called the floodplain region. It contains numerous char lands, and its width varies from place to place because of sandbars and natural levees. Such wetlands are especially concentrated in the Dhemaji and Barpeta districts.
11. Write about the geographic location and origin of Majuli.
Answer: Majuli is a large river island situated within the Brahmaputra river, covering an area of about 422 sq km. It was formed by the deposition of silt when the Brahmaputra and its tributaries changed their courses. Majuli was granted the status of a district in 2016; erosion and flooding are its major problems.
12. Write briefly about the boundaries and characteristics of the Barak Valley.
Answer: The Barak Valley lies in the southern part of Assam and is bounded by hills on its northern, southern and eastern sides. It includes the Barak plain along with its adjacent northern and southern foothills. Flowing about 225 km through the Cachar, Hailakandi and Karimganj districts, the Barak river has created a fertile alluvial plain.
13. Write briefly about the boundaries and characteristics of the Karbi Plateau.
Answer: The Karbi Plateau is basically a part of the Meghalaya Plateau, divided by the Kopili valley into two sections — eastern and western. The eastern part (Diphu, Bokajan) is nearly twice the size of the western part (Hamren). The plateau slopes towards the north-east and has been shaped by the Kopili and Barapani rivers.
14. Write briefly about the characteristics of the Barail range and the southern hills.
Answer: The Barail range extends westward from Nagaland into the Dima Hasao (North Cachar Hills) region. It connects the Naga hills with the Meghalaya Plateau. The Barail range divides Dima Hasao into two parts — the northern part slopes towards the Brahmaputra Valley and the southern part towards the Barak Valley.
15. Why is the amount of rainfall not uniform in all places of Assam?
Answer: Rainfall is not uniform across Assam because the physiographic structure, geographical location and presence of neighbouring hills differ from place to place. Mainly (a) topographic conditions, (b) location and (c) the presence of nearby hills cause the variation in rainfall.
16. Write briefly about the spatial distribution of rainfall in Assam.
Answer: The districts of Upper Assam (Tinsukia, Dibrugarh, Lakhimpur, Sivasagar) and some districts of Lower Assam receive more than 250 cm of rainfall annually. On the other hand, regions of Central Assam such as Nagaon and Karbi Anglong receive comparatively less, around 129 cm.
17. What are the reasons behind soil erosion in Assam?
Answer: The reasons behind soil erosion in Assam can be grouped into two. Physical causes: hilly slopes and waterlogging; and human-made causes: felling of trees (deforestation), unscientific cultivation, jhum cultivation, settlement and the excessive use of chemical fertilizers.
18. What are the different types of forests in Assam?
Answer: The forests of Assam can be divided into five types — (a) tropical evergreen forest, (b) tropical semi-evergreen forest, (c) tropical moist deciduous forest, (d) riverine forest and (e) tropical dry deciduous forest.
19. Write the names and location of the national parks of Assam.
Answer: Assam has five national parks — (a) Kaziranga (Golaghat, Nagaon, Sonitpur), (b) Manas (Chirang, Baksa), (c) Orang (Udalguri, Sonitpur), (d) Nameri (Sonitpur) and (e) Dibru-Saikhowa (Dibrugarh, Tinsukia).
20. Write how the wildlife sanctuaries maintain the ecological balance.
Answer: In wildlife sanctuaries, the killing and capturing of animals is prohibited, so the animals remain safe from poachers. The wild animals get a secure habitat and the natural vegetation is preserved, as a result of which the food chain remains intact and the ecological balance is maintained.
Long Answer
21. What is the type of Assam’s climate? Write briefly about its characteristics.
Answer: Assam has a sub-tropical monsoon type of climate. Its main characteristics are — heavy rainfall in summer, dry weather in winter, humidity throughout the year and comparatively mild temperatures. Because of the topography, geographical location and the influence of the sea, regional variation in climate is seen within the state itself. In summer the temperature rises to about 35 degrees Celsius, while in winter it falls to about 7 degrees Celsius. On the whole, the climate of Assam is humid, warm and rainfall-dominant.
22. Discuss briefly the geographical factors influencing the climate of Assam.
Answer: The main geographical factors that control the climate of Assam are — (a) its latitudinal position, (b) topography and the presence of hills and mountains, (c) proximity to the Bay of Bengal and the Indian Ocean, (d) the dominance of the south-west monsoon wind, (e) seasonal changes in air pressure and (f) local mountain and valley winds. Besides, the presence of rivers, wetlands and forests also influences the climate by controlling temperature and humidity.
23. What are the main seasons of Assam? Write briefly about the seasonal variation in the distribution of temperature and rainfall in Assam.
Answer: Assam has mainly four seasons — (a) the pre-monsoon season (March-May), (b) the monsoon season (June-September), (c) the retreating monsoon season (October-November) and (d) the dry winter (December-February). In winter the temperature falls to about 7 degrees Celsius and the weather remains dry; in the summer and monsoon seasons the temperature rises to about 35 degrees Celsius with heavy rainfall. The average annual rainfall is about 200 cm, though its spatial distribution is quite uneven.
24. Give a short account of the different types of soil found in Assam.
Answer: Mainly four types of soil are found in Assam. (a) Alluvial soil — found in the plains of the Brahmaputra and Barak valleys; it is very fertile and suitable for agriculture. (b) Piedmont soil — found in the foothill regions of the Himalayas. (c) Hill soil — found in the southern hilly regions. (d) Laterite soil — found in regions like Dima Hasao; it is poor in nutrients and less fertile. The nature of these soils determines the agriculture and vegetation of the respective regions.
25. Write about the changes in the administrative boundaries of Assam during the post-independence period.
Answer: After independence, the administrative boundaries of Assam changed several times. In 1947, Sylhet joined East Pakistan. After that, several states were separated from Assam — Nagaland in 1963, and Meghalaya, Mizoram and Arunachal Pradesh in 1972. As a result of this reorganisation, the capital of Assam was shifted from Shillong to Dispur. Though the state boundary has remained largely unchanged after 1972-73, the number of internal districts has increased from time to time.
26. Write the names of the present districts of Assam and their headquarters.
Answer: At present Assam has a total of 33 districts (seven new districts were created in 2015-16). The districts and their headquarters are — Baksa (Mushalpur), Barpeta (Barpeta), Biswanath (Biswanath Chariali), Bongaigaon (Bongaigaon), Cachar (Silchar), Charaideo (Sonari), Chirang (Kajalgaon), Darrang (Mangaldoi), Dhemaji (Dhemaji), Dhubri (Dhubri), Dibrugarh (Dibrugarh), Dima Hasao (Haflong), Goalpara (Goalpara), Golaghat (Golaghat), Hailakandi (Hailakandi), Hojai (Hojai), Jorhat (Jorhat), Kamrup (Amingaon), Kamrup Metropolitan (Guwahati), Karbi Anglong (Diphu), Karimganj (Karimganj), Kokrajhar (Kokrajhar), Lakhimpur (North Lakhimpur), Majuli (Garamur), Morigaon (Morigaon), Nagaon (Nagaon), Nalbari (Nalbari), Sivasagar (Sivasagar), Sonitpur (Tezpur), South Salmara-Mankachar (Hatsingimari), Tinsukia (Tinsukia), Udalguri (Udalguri) and West Karbi Anglong (Hamren).
Short Notes
27. South-West monsoon wind.
Answer: The south-west monsoon wind is the moisture-laden wind that blows from the sea towards the land during the summer season. From June to September this wind brings heavy rainfall to Assam, which helps agriculture but also causes floods.
28. North-east monsoon wind.
Answer: The north-east monsoon wind is the dry wind that blows from the land towards the sea during the winter season. During October-November this wind brings fog and a fall in temperature to Assam, and rainfall is generally low.
29. Administrative divisions of Assam.
Answer: For administrative convenience, Assam is divided into districts, sub-divisions, revenue circles and blocks. Since the reorganisation of 1973 the number of districts has increased, and at present Assam has a total of 33 districts, four of which fall under the BTAD.
30. District-level population of Assam.
Answer: According to the 2011 census, there is a considerable variation in population among the districts of Assam. In terms of population, Nagaon (about 28.2 lakh) is the largest and Dima Hasao (about 2.14 lakh) is the smallest district.
31. BTAD.
Answer: BTAD stands for the Bodoland Territorial Areas District. Formed in 2003 to fulfil the aspirations of the Bodo community, this area comprises four districts — Kokrajhar, Chirang, Baksa and Udalguri.
Extra Questions and Answers
1. Which is the largest river island of Assam?
Answer: The largest river island of Assam is Majuli.
2. For what is Kaziranga National Park world-famous?
Answer: Kaziranga National Park is world-famous for the one-horned rhinoceros.
3. Where does the Brahmaputra river originate?
Answer: The Brahmaputra river originates from the Chemayungdung glacier near Mount Kailash in Tibet.
4. Which two national parks of Assam have been given the status of UNESCO World Heritage Sites?
Answer: Kaziranga and Manas — these two national parks have been given the status of UNESCO World Heritage Sites.
5. Geologically, what is the nature of the physiographic structure of Assam?
Answer: Geologically, the physiographic structure of Assam is of very recent origin, showing floodplains, wetlands, scattered hillocks and old plateaus.
6. Where is the capital of Assam located?
Answer: The capital of Assam is located at Dispur, near Guwahati.
Key Terms
| Term | Meaning |
|---|---|
| Physiography | The study of the surface features and landforms of the earth. |
| Valley | A low stretch of land lying between two hills or mountains. |
| Monsoon wind | A seasonal wind that reverses its direction with the change of seasons. |
| Char land | A riverine island or sandbar formed by the deposition of silt within a river. |
| Alluvial soil | Fertile soil formed from the silt deposited by rivers. |
| Wildlife sanctuary | A protected area reserved for the conservation of wild animals. |