Here is a comprehensive guide to Chapter 1, “Assam in North East India: Its Environment, Physiography, Climate, Soil and their Relationship,” from the “Swadesh Adhyayan” textbook, created specifically for AHSEC Class 12 students.
Chapter 1: Assam in North East India
Here is a comprehensive guide to Chapter 1 from the “Swadesh Adhyayan” textbook, created to help you prepare thoroughly for your upcoming AHSEC Class 12 exams. This guide includes a summary, complete textual answers, previous years’ AHSEC questions, and other important questions.
Summary Note
This chapter provides a geographical overview of Assam within the context of North East India. North East India comprises eight states: Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Tripura, and Sikkim. The region is strategically sensitive as it shares about 99% of its total boundary with five foreign countries: Nepal, Bhutan, China, Myanmar, and Bangladesh.
Assam is the only major plain state in the region, located between 24°07′ N and 28°0′ N latitude and 89°5′ E and 96°1′ E longitude. Its climate is primarily wet sub-tropical, influenced by the monsoon winds, its location surrounded by hills, and the vast water body of the Brahmaputra river. The mighty Brahmaputra, often called the “lifeline of Assam,” is the sixth biggest river in the world and has a profound impact on the state’s environment and economy. It is a trans-Himalayan river that creates the world’s largest river island, Majuli, which is the heart of Sattriya culture. The Brahmaputra is also the second national waterway of India.
The soils of Assam are broadly divided into four types: alluvial soil (new and old), hill soil, coarse grain soil (Bhabar and Tarai), and red or laterite soil. These fertile soils and suitable climate make Assam ideal for agriculture, which is the mainstay of the state’s economy. The chapter concludes by highlighting Assam’s unique position as the central state in the North East, connecting the region to the rest of India through various modes of transport, and its high population density compared to other states in the region.
Complete Textual Question and Answer
1. (a) In which year the North Eastern Council was formed?
Answer: The North Eastern Council was formed to combine all the seven states of the North Eastern Region for economic development measures. (The text mentions its formation but not the specific year).
(b) When the state of Sikkim was put in North Eastern Region?
Answer: The state of Sikkim was included in the North Eastern Region in 2002, becoming the eighth state of the region.
(c) In which climatic zone the Assam is included?
Answer: Assam is primarily included in the wet sub-tropical climatic zone.
(d) What is the density of population per sq km in Assam as per 2011 Census?
Answer: As per the 2011 Census, the density of population in Assam is 397 per sq. km.
(e) What is the percentage figure of the Brahmaputra basin area that falls in Assam to the total area of the basin in India?
Answer: Of the total basin area of the Brahmaputra within India, 36.33 per cent falls in Assam.
(f) How many types of soils are there in Assam?
Answer: The soils of Assam can be divided into four main types: alluvial soil, hill soil, coarse grain soil, and red or laterite soil.
2. (a) How many states are there in North East India and what are the states?
Answer: There are eight states in North East India. The states are Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Tripura, and Sikkim.
(b) What are the prime aims and objectives of North Eastern Council?
Answer: The prime aims and objectives of the North Eastern Council are to take up certain economic development measures for the North Eastern Region.
(c) When and between whom the Yandabu Treaty was signed?
Answer: The historic Yandabu Treaty was signed in the year 1826 between the British and the Burmese.
(d) Which two states of North East India remained as the union territories from 1949 to 1972?
Answer: Arunachal Pradesh and Mizoram were recognised as Union Territories on 20th January 1972. Manipur and Tripura were also Union Territories from the time of independence until they were given full statehood on 21st January 1972.
(e) Which foreign countries surround the North East India?
Answer: The North East India region is surrounded by five foreign countries: Nepal, Bhutan, China, Myanmar, and Bangladesh.
(f) Why the Brahmaputra river is called as the trans-Himalayan river?
Answer: The Brahmaputra river is called a trans-Himalayan river because its source area is north of the Himalayas, and it flows through the region at a comparatively higher altitude than its source before entering the Assam valley.
3. (a) Give a short description of the Brahmaputra river course after entering India.
Answer: The Brahmaputra river, known as the Yarlung Tsangpo in Tibet, flows for 1700 km and then turns southward to enter Arunachal Pradesh, where it is known as the Siang. After flowing 278 km through mountain terrain, it enters the plain area near Pasighat, where it gets the name Dihang. About 52 km downstream, the Dihang confluences with the Dibong and Luhit rivers. From this confluence point, the westward flowing river is known as the Brahmaputra.
(b) Describe the role of the Himalayas in controlling the climate of Assam.
Answer: The lofty Himalayas play a crucial role in controlling Assam’s climate. They protect the entire region from severe cold waves coming from the north. The snow-covered slopes also keep the Brahmaputra and its north bank tributaries full of water throughout the year due to snowmelt. Furthermore, the presence of the Himalayan range and surrounding hills causes heavy orographic rain during the monsoon season.
(c) Describe the specialities of the Majuli island.
Answer: Majuli is the world’s biggest river island, situated amidst the Brahmaputra river. It covers an area of about 645 sq km and has 155 inhabited villages. Majuli is very rich in biodiversity and is considered the heart of the Sattriya culture. Its mask-making culture is also world-famous.
(d) Give a brief description of the Brahmaputra as a national river route.
Answer: On 1st September 1988, the Government of India declared an 891-kilometre course of the Brahmaputra river, from Sadiya to Dhubri, as the second national waterway of the country. Because the river is perennial, ships can navigate through it throughout the year, making it a viable national route for transport and commerce.
(e) Give a description in how many and what are the climatic seasons Assam has been divided.
Answer: The climate of Assam has been divided into four seasons: rainy (monsoon), winter, autumn, and spring. Of these four, the rainy and winter seasons are comparatively longer. The spring and autumn seasons are of short duration and occur between the winter and rainy seasons.
(f) Describe the influence of Monsoon wind in Assam.
Answer: The climate of Assam is highly influenced by the monsoon wind. The rainy season, often called the monsoon season, begins in the first week of June and continues until September, bringing heavy rainfall to the state. This heavy orographic rain occurs due to the presence of the hills and mountains surrounding the region, which causes the rivers to overtop and create floods in many places.
(g) Describe the distribution and characteristics of Laterite or Red soils in Assam.
Answer: Red or Laterite soil is found in specific parts of Assam. It is mainly found in the Dima Hasao district and the Hamren area of the Karbi plateau. It is also found in the southern margin of the Golaghat district and the foothill zone of the Barail range in the Barak valley. This soil has a high content of iron and aluminium particles, which gives it a red colour. It is generally dark in colour and has very little nitrogen, potash, phosphoric acid, and lime content.
4. (a) Explain the reasons for which Assam becomes rich in biodiversity.
Answer: Assam is rich in biodiversity due to several geographical factors. Its unique location, surrounded by hills and mountains, and its wet sub-tropical climate create ideal conditions for diverse flora and fauna. The mighty Brahmaputra river and its numerous tributaries and wetlands support a wide variety of aquatic species, including the rare freshwater dolphin, Platanish Gangetica. The presence of different soil types and heavy rainfall also helps in maintaining rich forest cover, which in turn supports a wide range of plants and animals.
(b) Write a note on the distribution and characteristics of alluvial soils of Assam.
Answer: The Brahmaputra and Barak valleys are mainly composed of alluvial soils. This soil is divided into two categories: new alluvium and old alluvium.
- New Alluvium: This is found in the frequent flood-affected areas on both banks of the Brahmaputra and Barak rivers. Its colour ranges from medium to dark grey.
- Old Alluvium: This is generally found in a belt between the new alluvium near the river banks and the foothills. It is found in districts like Kokrajhar, Barpeta, Nalbari, Kamrup, Darrang, Sonitpur, and Lakhimpur. The colour of this soil ranges from dark grey to greyish-yellow.
(c) Having plain physiography what are the advantages of Assam compared to other states of North East India? Discuss.
Answer: Assam’s plain physiography gives it several advantages over the other hilly states of the North East. Due to its fertile alluvial plains and suitable climate, Assam is highly suitable for extensive agricultural activities. This makes it the agricultural hub of the region. The plain terrain also makes it the central point for transportation and communication, with better-developed roadways, railways, and airways that connect the entire region with the rest of India. These factors contribute to a higher population density and make Assam the economic and logistical center of North East India.
(d) How the location peculiarity of Assam increased its importance in North Eastern region?
Answer: Assam’s peculiar location at the center of the North East has greatly increased its importance. It is the gateway to the entire region, and all transportation to other parts of the country—whether by road, rail, or air—must pass through Assam. This makes it the most crucial state for connectivity and commerce. Furthermore, being surrounded by five foreign countries, Assam holds immense strategic importance for the nation’s security. Its central location has made it the hub for the region’s economic and political activities.
