Class 12 Geography Chapter 23 Assam Geography The answer to each chapter is provided in the list so that you can easily browse throughout different chapters SCERT Class 12 Geography Chapter 23 Assam Geography and select need one.
Class 12 Geography Chapter 23 Assam Geography
Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board/NCERT Class 12 Geography Chapter 23 Assam Geography Solutions for All Subject, You can practice these here…
PHYSIOGRAPHY, DRAINAGE AND CLIMATE OF ASSAM
Q.1. Give a geographical account on the Barak Valley.
Ans :- The Barak Valley forms one of the important physiographic units of Assam. The valley comprising the Barak Plain and the northern and Southern foothills is the product of the flow-geomorphic processes of the river Barak and its Tributaries. The Barak Plain is banded by the foothills of the Barail range on the north and the foothills of Mizo hills on the South
The Barak river receives a large number of Tributaries. Of these the Jiri, Labak, Madhura, Dalu, Jatinga and Larang in the north bank and the Sonai, Katakhal, Dhaleswari, Singha and Langai in the south bank are the nain. As the plain has a law gradient, the Barak and its tributaries especially Dhaleswari and frequently meander. There are therefore, many on bow lakes especially on both banks of the Barak river. Occurance of isolated low hillocks in the plain indicates the erosional activities of the Barak and its tributaries Like the Brahmaputra plain the Barak valley also has plain embayments projected into the surrounding hills.
Q.2. Mention the three characteristics of the Brahmaputra river.
Ans :- The characteristics of the Brahmaputra river are –
(a) The Brahmaputra river of Assam forms a complex river system which is characterised by a dynamic and sediment transport pattem.
(b) It is one of the largest rivers in the world which passes through 3 countries. It is the fourth largest river in the world in terms average water discharge at the mouth with a flow of 19830ms
(c) The Brahmaputra has been evoking human interest since time immemorial with its vastness and mighty nature. There are mythological tales and folk-ores about its genesis and source both in India and Tibet.
Q.3. Write the role of rainfall in climate peculiarities of Assam.
Ans :- The state Assam lies in the regional monsoon climate of the sub tropical belt. It enjoys heavy summer rainfall. Assam experiences an average annual rainfall of 230 cm. During the winter (December to February) the average annual rainfall is 6 cm and in summer (March to May) it is about 64 cm. The maximum rainfall (146 cm) is experienced in June to September and 14 cm in October to November.
So far the spatial distribution of rainfall is concerned there is marked variation within the state. The unique physiographic features of the state and its surroundings mountains and hill ranges affect the areal distribution of rainfall. In general the hills and foothills receive more rainfall.
Assam may be divided into 3 district rainfall belts on the basis of nature of distribution of rainfall.
They are :
(a) Heavy rainfall belt includes Lakhimpur, Dhemaji, Dibrugarh, Tinsukia, Sivasagar, Jorhat, Dhubri, Kokrajhar, Bongningaon, Chirang, Goalpara, Cachar and Karimganj.
(b) Medium rainfall belt includes Barpeta Nalbari, Bagsha, Kamrup, Sonitpur, Morigaon, Nagaon, Golaghat, Karbi Anglong.
(c) Low rainfall belt includes part of Nagaon (Southern) district.
Q.4. Give an account on the atmospheric temperature condition in Assam.
Ans :- In different districts of Assam the mean annual maximum temperature i.e. July-August ranges from 30°c to 33°c, the minimum temperature i.n. December -January ranges from 8°c to 150. The two valleys of the state experience the highest temperature in July. They experience the latest temperature during January. The highest temperature recorded in three different places i.e. Dibrugarh in the easternmost part, Tezpur in the central part of the Brahmaputra valley are 37c, 36c and 37°c respectively. The lowest temperatures recorded in the three places are 6°c, 7°c and 8’e respectively.
Write short notes on :
Q.5. Duars plain
Ans :- The Doors or Duars are the feet plains and foothills of the easter Himalayas in North East India around Bhutan. There are 18 passages or gateways through which the bhutanese people can communicate with the people living in the plains. The Duars plain is divided by the sankosh river into Eastern and western Dooars consisting an area of 8,800 sq. km. The altitude of Duars ranges from 90 to 1750m. Innumerable streams and rivers flow through these fertile plains from the mountains of Bhutan. The economy of Duars is based on Tea, Tourism and Timber.
Q.6. The Karbi plateau
Ans :- The Karbi plateau generally belongs to the Meghalaya plateau and consists of two hilly lobes of unequal size, separated by the Kopili Valley. The eastern lobe covered by Rengma hills span over the entire Diphu district. It is approximately double the size of its western. It is dam shaped with altitudes ranging from 192 m to highest Dambak peak. The western lobe of the plateau spans to Meghalaya on the other hand, covers the Haven subdivision of the district. The plateau has a general shape from the south west to the south east. All the streams and rivers found here are tributaries of the Kapili and all of them flow from south west to north east.
Q.7. The Brahmaputra plain
Ans :- This plain has the Arunachal and Bhutan Himalayas to its north, the Patkai range and Arunachal hills to its east and Naga hills. Karbi Plateau and Maghalaya plateau to its south. It is the major physiographic unit of Assam. It is a narrow valley with an approximate east-west extension of about 720 km and Average width of 80 km. The plain is girdled by the Eastern Himalayas.
It is open in the west merging with the plains of west Bengal and Bangladesh. The 640 km long reach of the Brahmaputra and its 32 mauza north and South Bank tributaries drain the plain which covers about 72 percent of the total area of Assam. The plain as a whole greatly shapes from north east to south west with an average gradient of 13 cm per Km.
Q.8. The Barak valley
Ans :- The Barak Valley forms one of the important physiographic units of Assam. The valley comprising the Barak plain and the northern and southern foothills is the product of the fluvio geomorphic processes of the river Barak and its tributaries. The plain is enclosed by hill ranges on three sides – The Meghalaya Plateau and the Barail range of the NC Hills district on the North. Manipur Hills on the east and the Mizo Hills on the south. The Barak valley is the headward piedmont part of the Bank Surama-Kushiyara plain which lies largely in Bangladesh. The Barak plain shapes down gently to the west and river Barak flows sluggishly in meandering course through it leaving a series of ox-blow lakes and swamps.
Q.9. Rain shadow zones of Assam
Ans :- Assam may be divided into 3 district rainfall belts on the basis of nature of distribution of rainfall. These regions are as follows :
(a) Heavy Rainfall belt : It includes the districts of Lakhimpur Dhemaji, Dibrugarh, Tinsukia, Sibsagar, Jorhat, Dubri, Kokrajhar Bongaigaon, Chirang BTAD, Goalpara, Cachar and Karimganj.
(b) Medium rainfall belt : It includes the districts of Barpeta, Nalbari, Baksa BTAD, Kamrup, Darrang, Udalguri BTAD, Sonitpur, Morigaon, Nogaon, Golaghat & Karbi Anglong.
(c) Low rainfall belt : It includes the southern part of Nagaon district which may include the northern part of Meghalaya (Khasi and Jaintia districts), Hojai, Lanka and Lumding to Bokajan the places are included in this belt.
Q.9. The ‘Chars’ of the Brahmaputra River.
Ans :- The rapid monsoonal rain, easily erodible rocks, steep hills and high seismicity contribute a substantial amount of sediment to the Brahmaputra. The river with such a high volume of water discharge and sediment load, represents the most dynamic fluvial regime. Its wide alluvial channel in Assam having an average width of 6-8 km is dotted with more than 600 small and large sand bars, locally called as chars. The chars are formed due to the variability of flow of water, excessive sedimentation. The inhabitant who lived in the bank of river low preferring this char for cultivation and even for their habitat. In the district of Barpeta, Goalpara and Dhubri a number of chars are found in the Brahmaputra.
Q.10. The river islands of the Brahmaputra River.
Ans :- The Brahmaputra contains a member of islands but out of these only two is most significant. They are the world’s largest river island called Majuli and the world’s smallest river island called Umananda.
Umananda is the smallest river island in the midst of river Brahmaputra flowing through the city of Guwahati Assam.
Majuli is bounded between 26 44 and 27-15 N latitudes and 93 39 and 94 35 longitudes is situated within the river Brahmaputra. Majuli has its own history of genesis of the southward migration of the Brahmaputra which is an important fluvio-geomorphic process of the river. In fact, Majuli was an integral part of the jorhat district of Assam on its south bank.
Q.11. The Barak river basin.
Ans :- The river Barak has its origin in the high Hill complex of Mao and south east of Java Peak. It runs westward for some distance forming the boundary of Nagaland and Manipur and then takes a sudden southward turn and flows through Manipur until it reaches Tipaimukh at the South western comer of the state. It then takes a sharp U-turn and forms firstly the boundary between Manipur and Mizoram and then Manipur and Cachar district of Assam.
Thus, flowing for about 60kms it again turns sharply westward at Jirimukh and flows through the cachar plain sluggishly. In the western part of Cachar Plain the river gives out two branches near Bhanga. While the northern branch is known as the Surma, the Southern branch is called Kusiyara. The total length of Barak is 85 Km in Assam and it has a catchment area of about 50,000 sq. Km within North-East India of which about 8000 sq. km falls within Assam.
Q.12. Give a short description of the Barail Range.
Ans :- The Barak river originates from the Barail range in the border areas of Assam, Nagaland and Manipur and flows through the district of cachar. The Barail range is located between 92°52°50 Easto 250.17 North. It covers an area of about 80000 hectares and the altitude ranges from 100-1,959 m. The Barail is the highest hill range in Assam. It includes the North Cachar Hill reserve forest of Cachar Hill. The Barail range is the watershed between Brahmaputra and Barak rivers. The climate is tropical monsoon type. The highest peak is Laika (1959 m). The annual rainfall varies from 2000 mm to more than 6000 mm. The westernmost part of the range receives the heaviest rainfall in Assam.
Q.13. Give the reasons why river erosion is maximum in the Barait Range than that of the other highlands of Assam.
Ans :- The rivers erosion is found to be maximum in the Barail Range because
(a) The annual rainfall varies from 2000 mm to more than 6000mm. The westernmost part of the range receives the heaviest rainfall in Assam.
(b) The people of Barail foot hills practices mainly Jhum cultivation which may lead to soil erosion.
(c) The range has steep slopes which may be a factor of soil erosion.
Q.14. Which are the common landforms developed by river erosion in Barail Range?
Ans :- The ranges in North Cachar Hills are known as the Barail Ranges. The successive parallel ranges become lower both to the Brahmaputra plain in the North and to the Barak plain in the South. The main Barail range acts as the common watershed of Brahmaputra basin and Barak Basin. Because the area is under hot and humid climate conditions, the processes of weathering and erosion are very active leading to the development of deep valleys and gorges and stereo slopes. There are many rivers and streams on both sides of the Barail ranges. The Barak Plain is Horse shoe shaped with about 85 km of East West extension.
Q.15. What are the characteristics of mid channel bars of the Brahmaputra River?
Ans :- The Brahmaputra has two important channels each of which branches out from the river Brahmaputra and joins it about 100 km downstream. The first one is the Kharikatia-Luhit, which appears to separate from the main river in the right bank, opposite to Dihingmukh and meets it again at Luhitmukh, east of Kaziranga, forming the northern boundary of Majuli Island.
The Sound channel is Kolang the branches out at Arikatimukh western part of Kaziranga (near Silghat) flows through the Nagaon-Morigaon plain, meet with the Kapili and the Digaru and falls into the Brahmaputra again at Kazalimukh east of Chandrapur.
Q.16. What are the characteristics of Trans Himalayan Rivers?
Ans :- The trans-Himalayan originate beyond the Great Himalaya. These are the Indus, the Sutlez and the Brahmaputra rivers. The Indus system is situated to the North of Ladakh range and Kailash Range, it rises near the Mansarovar Lake at an altitude of 5180 m. It enters the Indian Territory in Jammu and Kashmir where it receives Himalayan tributaries such as Gartang, Zaskar, Dras, Shyok, Shigar, Nubra etc. Indus with a length of 2880 km is considered as one of the largest rivers of the world. Many urban colonies are located beside the Indus river in Ladakh such as Moral, Leh, Bunji and Skardu.
The Sutlej river originates from Kailash, close to the most sacred lake of Mansarovar. In Kinnaur district the river flows side by side with the Hindustan Tibet lead at Karcham in Kinnaur, the Barpa river meets the sutlej with its bheem and crystal clear water.
Q.17. Discuss the characteristics of the Plateau zone of Assam.
Ans :- The Plateau region which has developed on the old crystalite massif of Gondwanaland now termed as Karbi plateau. The Karbi plateaus can be found in two separate parts –
(a) Central Karbi Plateau : It is looking like a guava with its stalk towards the south. This is because, as it is isolated from the Hamren side by the Kapili and its headstreams. So also it is isolated from Naga Hills by the Dhansiri River and its headstreams like Deepani, Bokajan, Naojan ete. It has the Dhansiri plain (Golaghat) to its cast and the Kalong-Kapili plain (Nagaon) to its west. The plateau is eroded and fairly subdued by age-old weathering and erosion under Hot and Humid tropical monsoon conditions. The main features of this plateau is (i) There is a series of waterfalls. (ii) It has a low lying east west corridor in its middle part
(b) Hamren plateau : It rises in height from Lanka, Hozai, Jogjan, Garubat and shahari foothills of Nagaon towards Jaintia Hills. The important rivers of this plateau from the west are Umiam or Killing. Karbi Langpi. Umkhim or Barapani, Umud, Amlong or Kolonga, Amring and finally the Kapili which forms the eastern boundary of the Plateau. The highest peak of this region lies in between Karbi Langpi and Umiam rivers.
Q.18. Discuss the characteristics of the hills and hillocks of the Barak Valley.
Ans :- The Southern part of Assam is occupied by the Barak Plain, which is relatively a small one. It is encircled on the north by the North Cachar (Barail) Hills, on the east by the Monipur Hills and on the south by the Lusai (Mizoram) Hills.
The hill ranges which lie in the north in North Cachar Hills and in Mizoram in the south area of north south alignment. Following the same alignment one can locally be known as ’tila’s. These tiles are made of sedimentary rocks of Tipen (Miocene) series.
Hi, I’m Dev Kirtonia, Founder & CEO of Dev Library. A website that provides all SCERT, NCERT 3 to 12, and BA, B.com, B.Sc, and Computer Science with Post Graduate Notes & Suggestions, Novel, eBooks, Biography, Quotes, Study Materials, and more.
