Geography of Assam
1 . What are the geographical divisions of Assam?
Answer: The topography of Assam can be divided into four main parts namely a) Brahmaputra Valley, b) Barak Valley, c) Karbi Plateau, d) Barail and Southern Mountains.
2. What is the geo-natural region of Brahmaputra valley?
Answer: The geographical regions of the Brahmaputra Valley are the northern foothills, the plains on the north and south banks of the Brahmaputra, the floodplains and char-chapri regions of the Brahmaputra, and the southern foothills.
3. Name the four major tributaries of the Brahmaputra on each of its north and south banks.
Answer: The four tributaries of the Brahmaputra on the north bank - Sovansiri, Ranganadi, Burai and Bargang. There are four tributaries of the Brahmaputra on the southern bank - Budhidihing, Dishang, Dikhou and Janji.
or
The Brahmaputra Valley is divided into four geographical regions namely: (a) Northern Foothills (b) Plains on the north and south banks of the Brahmaputra (c) Brahmaputra floodplains and char-chaparis and (d) Southern Foothills.
4. Briefly describe the Brahmaputra plain region.
Answer: The plains of the Brahmaputra refer to the plains on its north and south banks. The northern coastal plain extends from the northern foothills to the Brahmaputra River in the south and the southern coastal plain extends from the southern foothills to the northern Brahmaputra River. The plains on both sides of the Brahmaputra are formed by the accumulation of rock, sand and mud carried by the Brahmaputra and its numerous tributaries from the highlands of the north and south. The plains north and south of the Brahmaputra are composed of alluvial soils and are suitable for agriculture. It is densely populated and has good transportation. The northern coastal plain is about 30 km wide on average in the southern part and steep on average about 10 km wide in the southern part. The southern coastal plain is only about 5 km wide on average in Kamrup, Goalpara and Dhubri districts due to the expanse of the Meghalaya Plateau. Like the north coast, the plains of the south coast are densely populated. The fertile land is good for agriculture and the transportation system has improved.
5. Briefly describe the Brahmaputra floodplain region.
Answer: The Brahmaputra floodplain is the area of occasional or frequent flooding between the plains on the north and south banks of the Brahmaputra and the char-chapari area along its banks. This floodplain, however, is not equally wide everywhere. The width of the floodplain has decreased in some places due to loose embankments in places along the banks of the Brahmaputra and the accumulation of river banks. There are numerous beaches and reservoirs on the north bank of the Brahmaputra, especially in the floodplain areas of Dhemaji and Barpeta districts. The floodplain on the southern bank is relatively steep. The char chapri area between the streams of the Brahmaputra River is called an active floodplain.
6. Write about the geographical location and origin of Majuli.
Answer: Due to the vastness of the Brahmaputra River and its active mining, transport and sedimentation processes, it is naturally unstable and its streams change course frequently. The Brahmaputra River is a burning problem in Assam. There are more than 600 sand dunes on the banks of the river. Some of these sandbars are permanent and some are semi-permanent and most are temporary. In addition to the dredging, transportation and sedimentation processes along the river banks, the size, shape and location of these chars change under the influence of floods. This is how the Majuli River-Island is formed on the banks of the Brahmaputra. It is known to be one of the largest river islands in the world. According to the 2011 census, Majuli has a population of about 1.68 lakh and covers an area of about 422 sq km and is currently declared a district. There are many problems in Majuli, including floods and erosion. The area of Majuli is decreasing every year due to floods.
7. Briefly describe the boundaries and characteristics of the Barak Valley.
Answer: Like the Brahmaputra Valley, the Barak Valley is one of the most important geo- natural regions of Assam. The Barak Valley is formed by the Barak Plain and its adjacent northern and southern foothills. The Barak River flows in Assam from east to west through Kachar district and along the northern border of Hailakandi and Karimganj districts for about 225 km. The Barak and its tributaries have accumulated sediments carried from the highlands of the north and south to form the Barak plain. This plain is also known as the Kachar Plain. It is surrounded by mountains to the north, south and east. It is bordered by the Meghalaya Plateau and the Barail Mountains of North Kachhar Hills District to the north, the hilly region of Manipur to the east and the Mizo Mountains to the south. However, to the west, the plain joins the Kuchiara-Surma river plain in Sylhet district of Bangladesh.
8. Briefly describe the boundaries and characteristics of the Karbi Plateau.
Answer: The Karbi Plateau is part of the Meghalaya Plateau in terms of its origin and geological structure. The Karbi Plateau is divided into two parts by the Kapili Valley, east and west. The eastern part covers the Rengma Hills and extends to Diphu and Bokajan sub-divisions of Karbi Anglong district. This fragment is about twice as large in size as the western fragment. The western section covers Hamren sub-division of Karbi Anglong district. The section slopes from southwest to northeast and has an average elevation of 900 m. The western part is shaped by the Kapili and Barapani rivers and their tributaries.
9. Briefly describe the characteristics of the Barail and Southern mountain ranges.
Answer: Barail and Southern Mountains The Barail Mountains extend westwards from Tuensang in Nagaland and part of them extends in Dima Hasao district of Assam. The Barail Mountains actually connect the Naga Mountains in the east and the Meghalaya Plateau in the west and also divide the North Kachar Hills into two parts. The northern slope also belongs to the Brahmaputra Valley and the southern slope also belongs to the Barak Valley. The north slope is also relatively flatter than the south slope.
10. The climate of Assam belongs to which category? Briefly describe its characteristics.
Answer: Assam is geographically belonging to the subtropical monsoon climate. Assam experiences heavy rains in summer, dry winters and high humidity and relatively low temperatures almost all the time. The climate of Assam is mainly influenced by monsoon winds but the geographical diversity of the state makes its climate quite diverse. The climatic characteristics of the state are not the same everywhere due to differences in geographical location, topography, waters of the Arabian Sea, Bay of Bengal, Indian Ocean and South-West Humid Monsoon. The climate of Assam is also affected by the seasonally changing air pressures of the North-West India region. In addition, locally flowing mountain winds, valley winds and the presence of rivers and other water bodies have a significant impact on climate characteristics at the local level. In summer, the air in the plains of the Brahmaputra and Barak valleys is slightly warmer than in the adjacent mountainous regions.
11. What is the main cause of rainfall in Assam during summer?
Answer: Summer rains in Assam are mainly caused by lithofacies and cyclones of moist south-westerly monsoon winds. This is the main reason for the rainfall in Assam.
12. Briefly discuss the geographical factors affecting the climate of Assam.
Answer: Assam geographically belongs to the subtropical monsoon climate. The Himalayas and their ridges extend to the north and east of the Brahmaputra and Barak valleys and block the warm and humid monsoon winds from the south-west in summer. The mountain range also protects the state from the cold winds blowing from the Tibetan Plateau towards India in winter. In summer, clouds carried by the south-westerly monsoon winds cross the southern mountainous regions including the Meghalaya plateau and cause heavy rains in the Brahmaputra valley, especially in the northeastern part. In addition, the south-westerly monsoon winds are interrupted in the mountainous areas on almost three sides of the Barak Valley and heavy rains are also caused in the Barak plains. Rainfall decreases significantly on the slopes of the mountains, especially in the eastern part of the Karbi Hills and in the northern and eastern parts of the Dima Hasao Hills. For the same reason, the southern part of Nagaon district receives very little rainfall. Summer rains in Assam are mainly caused by lithofacies and cyclones of moist south-westerly monsoon winds. The dry northeast monsoon winds absorb some water vapor from the Brahmaputra River and its tributaries and sometimes cause some rainfall in the south-western part of Assam during winter. The unique topography and location of the State and the influence of the adjacent mountainous terrain cause variations in the distribution of rainfall. Rainfall is usually highest in the mountainous and foothills.
13. What are the main seasons of Assam? Briefly describe the seasonal distribution of temperature and rainfall.
Answer: The main seasons in Assam are pre-monsoon, monsoon, return monsoon and dry winter.
During the pre-monsoon season, there are comfortable mornings, warm afternoons, tiring evenings and sudden, sometimes brief, lightning rains in the evenings or at night. Over time, heavy rains occur more frequently during this period.
Winter is followed by the pre-monsoon season, when the atmospheric temperature rises slowly from the beginning. Spring season prevails in Assam during this pre-monsoon season.
The monsoon season lasts from early June to late September. During this period, moderate to heavy rains are received almost continuously in various parts of the state (Assam) under the influence of south-westerly monsoon winds. The highest rainfall during this period occurs in June, July and August.
During the return monsoon, temperature and rainfall decrease due to the end of the rainy season. The decrease in temperature causes the air pressure in the state to increase and therefore the air flow is completely reversed from northeast to southwest. The temperature drops during this period, causing fog at night and in the morning.
Winter in Assam is characterized by low temperatures, dense fog in the morning and a very dry condition with lack of rainfall. Therefore, December and January are the dryest months of the year and January is the coldest.
14. Name the two places with the highest and lowest rainfall in Assam and the amount of rainfall.
Answer: Highest rainfall in Assam and amount of rainfall - North Lakhimpur, 335 per cm.
Lowest rainfall and amount of rainfall in Assam: Lamding, 129 mm per cm.
or
Lakhimpur receives the highest rainfall in Assam. It receives an average of 336 cm of rainfall per year. Lamding receives the lowest rainfall in Assam. The average annual rainfall is 129 cm.
15. Why doesn't all parts of Assam receive equal amount of rainfall?
Answer: The unique geography and location of Assam and the influence of the adjacent mountainous terrain causes variations in the distribution of rainfall. Therefore, rainfall is not equal in all parts of Assam.
16. Briefly write about the spatial distribution of rainfall in Assam.
Answer: A study of the rainfall in different parts of Assam shows that there is a significant spatial variation in rainfall in the State. The unique topography and location of the State and the influence of the adjacent mountainous terrain cause variations in the distribution of rainfall. Rainfall is usually highest in the mountainous and foothills. In addition, Tinsukia, Dibrugarh, Dhemaji, Lakhimpur and Sibsagar districts in southern Assam, Kokrajhar and Dhubri districts in southern Assam and Kachar, Karimganj and Hailakandi districts in southern Assam receive more than 250 cm of rainfall per annum. Nagaon and Karbi Anglong districts in central Assam received very little rainfall. The Lanka-Lamding area of Nagaon district receives only 129 cm of rainfall annually.
17. Briefly describe the types of deaths found in Assam.
Answer: The dead bodies found in Assam can be divided into four types. such as -
1) Sedimentary dead,
2) Giripada Mrivika,
3) Mountain dead,
4) Concrete death.
1. Sedimentary debris: This debris is moderately thick and smoky in appearance. It is mainly composed of sand and sedimentary mud and is slightly acidic. These soils are usually almost free of phosphoric acid, nitrogen and humus.
2. Mountainous Mrioka: Mountainous Mrioka is found in the steep foothills of the northern Himalayan foothills of the Brahmaputra Valley. The mountainous region is also composed of clouds and starry regions. This dead body has a thick layer.
3. Mountain Deer: Mountain Deer are usually found in the mountainous regions of southern Assam. The fertility of this death varies from place to place. They are rich in nitrogen and organic matter. Based on their natural structure and chemical properties, these soils can be divided into two types - red sandy soils and red sediment soils.
4. Kankar Mrioka: Found almost throughout Dima Hasao district and some parts of southern Karbi Plateau. It is also found on the eastern border of Hamren sub-division of Karbi Anglong district, on the southern border of Golaghat district and at the foot of the Barail Mountains in the northern part of the Barak plain. They are usually black in color and have a mainly sandy structure. It is low in nitrogen, potash, phosphoric acid and lime.
18. What are the causes of mortality decline in Assam?
Answer: Death in Assam is affected by some natural and man-made factors. Natural factors include natural erosion on mountain slopes, waterlogging problems in plains and lowland areas. Man-made factors include:
a) Surface death caused by increased surface runoff due to deforestation.
b) Unscientific plowing of sloping land.
c) Jhum cultivation in hilly areas.
d) Artificial damming problems caused by human settlement and other activities.
e) Application of excessive amounts of chemical fertilizers in the fields for increased crop production.
19. What is the present population of Assam?
Answer: The current population of Assam is 31.16 million.
or
Assam has a population of 31.16 million as of 2011 census.
20. What are the forests of Assam?
Answer: The forests of Assam can be divided into five main categories -
a) Tropical evergreen forests,
b) Tropical moist deciduous forests,
c) Tropical semi-evergreen forests,
d) Riverine forests,
E. Tropical arid or dry deciduous forests.
21. What is a rainforest? Write down the characteristics of the rainforests of Assam.
Answer: This forest is found in the rainfall areas of the state. The forest is also called a rainforest as it is found in areas with an annual rainfall of 300 cm or more.
Rainforest forests are observed to be three-layered. First, the layer consists of very tall trees. The rainforest forests of Assam are home to very tall trees like Holong and Macai. Trees slightly less tall form the second layer. Trees like Nahar, Chia Nahar, Amari etc. are commonly seen in this layer. The lowest layer contains pressure trees and forests. In addition to trees, rainforest forests also contain various plants, stars, bamboo, cane, parrot flowers, etc.
22. Briefly write about the importance and current crisis of riverine forests.
Answer: Many parts of Assam were once surrounded by riverine forests. Such forests are usually dominated by some tall trees and grasses. The trees include Chom, Sowalu, Uriam, Maj, Au, Azar, etc. Riparian areas are particularly suitable for arched trees or grasses like reed, goat, star, cotton, cane, jhao, kahua etc. National Parks or Sanctuaries like Kaziranga, Dibru-Saikhowa, Pabitra, Orang etc. are mainly located in riverine areas.
In recent times, riverine forests are shrinking rapidly due to the expansion of population to riverine areas.
23. Write the location and area of Kaziranga National Park.
Answer: Kaziranga National Park is located in Golaghat, Nagaon and Sonitpur and covers an area of 858.98 sq. km.
or
The Kaziranga National Park is located in the districts of Galghat, Nagaon and Shenitpur in Assam. It covers an area of 858.98 sq km.
24. Write the names and locations of the National Parks of Assam.
Answer: The names and locations of the National Parks of Assam are- National Park Name: Location (District) Kaziranga National Park: Golaghat, Nagaon and Sonitpur Manas National Park: Chirang and Baxa Orang National Park: Odalguri and Sonitpur Nameri National Park: Sonitpur Dibru-Saikhowa National Park: Dibrugarh and Tinsukia
25. Write how sanctuaries maintain the natural balance.
Answer: Sanctuaries play a far-reaching role in nature conservation. These are protected from the destructive influence of man. These cover a total area of 3,592.94 sq km. These protected forests are home to many wildlife species including elephants, tigers, rhinos, wild buffaloes, various deer and several species of monkeys. These protected forests with grasslands, trees and wetlands attract many tourists from home and abroad. The future of biodiversity in our state will depend largely on proper protection of these.
26. Write about the changes in the administrative department of Assam in the post-independence period.
Answer: During the partition of India in 1947, Sylhet was also separated from Assam and joined East Pakistan (now Bangladesh). As a result, there were 11 districts at that time and Shillong was the capital of Assam. Later, Nagaland seceded from the state of Assam in 1963, Meghalaya in 1970 and Mizoram in In 1973, the capital of Assam was established at Dispur, Guwahati. There are currently 33 districts in Assam. Seven of these districts were newly formed in 2015-1 Of these 33 districts, 4 districts belong to BTAD.
27. What is the area of Assam? Where is the capital of the state located? Name the largest and smallest districts by area.
Answer: Assam covers an area of 78,438 sq km. The largest district is Karbi Anglong (10,434 sq km) and the smallest district is Kamrup Metropolitan City (955 sq km).
28. What is the population of Assam according to the 2011 census? Name the largest and smallest districts in the state by population.
Answer: The population of Assam is 31.20 million. The largest district in the state is Nagaon (2.82 million) and the smallest is Dima Hasao (2.14 lakh).
29. Write a brief:
a) Assam and Monsoon Climate: Assam geographically belongs to the subtropical monsoon climate. The state experiences heavy rains in summer, dry winters and high humidity and relatively low temperatures almost all the time.
b) South-West Monsoon: During summer, clouds carried by the South-West Monsoon cross the southern mountainous regions including the Meghalaya Plateau and cause heavy rains in the Brahmaputra Valley especially in the northeastern part. The amount of rainfall usually varies annually depending on the strength of these monsoon winds and the accompanying variations in water vapor. Part of the south-westerly monsoon crosses the Meghalaya Plateau and another part enters through the western part of the state and causes rainfall in the southern Brahmaputra Valley region. Summer rains in Assam are mainly caused by lithofacies and cyclones of moist south-westerly monsoon winds.
c) Northeast Monsoon: The wind currents that form in the southern Brahmaputra Valley during winter and flow towards the Bay of Bengal are called Northwest Monsoon or Return Monsoon. The dry northeast monsoon winds absorb some water vapor from the Brahmaputra River and its tributaries and sometimes cause some rainfall in the south-western part of Assam during winter.
d) Monsoon season of Assam: The monsoon season is actually the monsoon season in Assam. The season lasts from early June to late September. About 70 per cent of the total annual rainfall in Assam falls during this period.
e) Pre-monsoon season in Assam: The pre-monsoon season in Assam lasts from early March to late May. This period comes after winter and the atmospheric temperature starts to rise slowly from the beginning. Spring season prevails in Assam during this pre-monsoon season.
f) Spatial distribution of rainfall in Assam: A study of the rainfall in different parts of Assam shows that there is a significant spatial variation in rainfall in the State. The unique topography and location of the State and the influence of the adjacent mountainous terrain cause variations in the distribution of rainfall. Rainfall is usually highest in the mountainous and foothills. In addition, Tinsukia, Dibrugarh, Dhemaji, Lakhimpur and Sibsagar districts in southern Assam, Kokrajhar and Dhubri districts in southern Assam and Kachar, Karimganj and Hailakandi districts in southern Assam receive more than 250 cm of rainfall per annum. Nagaon and Karbi Anglong districts in central Assam received very little rainfall. The Lanka-Lamding area of Nagaon district receives only 129 cm of rainfall annually.
g) Administrative Division of Assam: During the partition of India in 1947, Sylhet was also separated from Assam and joined East Pakistan (present-day Bangladesh). As a result, there were 11 districts at that time and Shillong was the capital of Assam. Later, Nagaland seceded from the state of Assam in 1963, Meghalaya in 1970 and Mizoram in In 1973, the capital of Assam was established at Dispur, Guwahati. There are currently 33 districts in Assam. Seven of these districts were newly formed in 2015-1 Four of these 33 districts fall under the BTAD.
h) Population of Assam at District Level: The geographical extent of Assam has changed considerably over time. Assam was quite large during the British rule. At that time, besides Meghalaya and Nagaland, Sileto (now part of Bangladesh) was with Assam. In 1895, the Lushai Hills (present-day Mizoram) became part of Assam. However, during the partition of India in 1947, the Sylhet part was separated from Assam and joined East Pakistan (now Bangladesh). As a result, there were 11 districts in Assam at that time and Shillong was the capital of Assam. Later, Nagaland seceded from the state of Assam in 1963, Meghalaya in 1970 and Mizoram in In 1973, the capital of Assam was established in Dispur, Guwahati. From that 1971 to the present ( 2014 ) the area and geographical boundaries and extent of Assam remain the same. Assam currently covers an area of 78,438 sq km and has a population of 31.20 million (2011 census). New districts have been formed in the same area of the state only to meet some administrative facilities and aspirations of different communities living in the state. There are currently 33 districts in Assam. Seven of these districts were newly formed in 2015-1 Of these 33 districts, 4 namely — Kokrajhar, Chirang, Baxa and Odalguri belong to BTAD ( Bodoland Territorial Area Districts ). BTAD was formed in Until 2015, Karbi Anglong district was the largest (10,434 sq km) and Kamrup Metropolitan District was the smallest (955 sq km). According to the 2011 census, Nagaon district has the highest population (2.82 million) and Dima Hasao has the lowest population (2.14 lakh).
f) BTAD- 4 out of 33 districts of Assam namely Kokrajhar, Chirang, Baxa and Odalguri belong to BTAD. BTAD was formed in
Editing By:- Lipi Medhi
