NCERT of Social Science | Class 7th | Part – I

CH1. Geographical Diversity of India

The Himalayas

• The Himalayas form a massive mountain wall stretching across six Asian countries: India, Nepal, Bhutan, China, Pakistan, and Afghanistan; their altitude can be understood from the map legend, and many peaks rise above 8,000 metres, together called the ‘Eight Thousanders’. Mount Everest is the highest mountain in the world.
• In summer, melting Himalayan snow feeds major rivers such as the Ganga, Indus, and Brahmaputra; these rivers and their tributaries supply water for drinking, farming, and industrial use, supporting hundreds of millions of people, which is why the Himalayas are called the ‘Water Tower of Asia’.
• The Himalayas are culturally and spiritually important because the mountains are considered sacred, and temples and monasteries built there attract monks and spiritual seekers who come to pray and meditate.
• The Bhagirathi River, a major tributary of the Ganga, originates from Gaumukh (meaning ‘Cow’s Mouth’) in Uttarakhand, at the edge of the Gangotri Glacier; this glacier is one of the largest in the Indian Himalayas, is considered sacred, attracts many pilgrims, and Gaumukh is a popular trekking destination.
• The Himalayas were formed when India, once part of the larger landmass Gondwana alongside Africa, broke away and moved north; about 50 million years ago, it collided with Eurasia, causing the land between them to crumple and rise like a pushed carpet, forming the Himalayan mountains.
• India continues pushing into Asia at about five centimetres per year, making the Himalayas grow taller by about five millimetres each year, which adds up to about five metres over a millennium.
• The word ‘Himalaya’ comes from Sanskrit: hima means ‘snow’ and ālaya means ‘abode’ or ‘dwelling’, so it means ‘abode of snow’.
• The Himalayas are broadly divided into three main ranges: the Himadri (Greater Himalayas), the highest and most rugged part, home to peaks such as Mount Everest and Kanchenjunga, remaining snow-covered throughout the year with harsh conditions and few human settlements; the Himachal (Lower Himalayas), south of the Greater Himalayas, with a moderate climate, rich biodiversity, and human habitation, including hill stations such as Nainital (Uttarakhand), Darjeeling (West Bengal), Shimla (Himachal Pradesh), and Mussoorie (Uttarakhand); and the Shivalik Hills (Outer Himalayas), the outermost and lowest range of rolling hills and dense forests, rich in wildlife and forming a transition between the Himalayas and the Gangetic Plains (Northern Plains).
• In the western Himalayan region, the traditional house-building method is called ‘kath-kuni’ or ‘dhajjidewari’, using locally available stone and wood to keep houses warm and resist damage during mild earthquakes.
• The Great Himalayan National Park in Himachal Pradesh has wide diversity of flora and fauna, has been declared a UNESCO World Heritage Site, and its biodiversity is preserved by both the government and village communities living inside the park.

The Cold Desert of India

• A desert is commonly imagined as a hot place, but cold deserts also exist, and India has one in Ladakh, where winter temperatures fall below –30°C.
• Ladakh receives very little rainfall and has a rugged landscape of rocky terrain, deep valleys, and lakes such as Pangong Tso; the word ‘tso’ means lake.
• Ladakh’s terrain resembles the surface of the moon, so it is called ‘moonland’; geologists explain that this terrain formed when mountains were folded during the collision of the Indian landmass with Eurasia.
• The folded region was once part of an ocean, so its rocks are largely made of sand and clay; over time, wind and rain eroded the mountains into their present shapes.
• Despite its harsh conditions, Ladakh supports unique wildlife including snow leopards, ibex, and Tibetan antelopes.
• The Ladakhi people lead a simple life, and the region is famous for its ancient monasteries and colourful festivals such as Losar and the Hemis Festival.

The Gangetic Plains

• Moving southwards from the Himalayas, we reach the vast and fertile Gangetic Plains, which have been an important part of India’s history and civilisation.
• These plains are nourished by mighty rivers originating in the Himalayas, especially the Ganga, Indus, and Brahmaputra river systems along with their extensive network of tributaries, providing a vital lifeline of water.
• The rivers carry minerals that enrich the soil, making the Northern Plains highly fertile and ideal for abundant agriculture.
• The rivers are also used to generate electricity, and a large proportion of India’s population lives in these plains.
• The flat land of the Northern Plains has enabled the development of an elaborate transportation network; roads and railways help move people and goods over long distances.
• The Ganga, Brahmaputra, and other rivers have been used for travel and trade for millennia.
• Most rivers are named after goddesses, such as Ganga, Yamuna, and Kaveri, but the name Brahmaputra means ‘the son of Brahma’.
• The Brahmaputra becomes bigger during summer instead of drying up because melting Himalayan snow and glaciers increase its water flow during that season.

The Great Indian Desert or Thar Desert

• Moving westward on the map, the yellowish area is the Thar Desert, a vast arid region with golden sand dunes, rugged terrain, and a wide-open sky.
• Sand dunes are formed when wind shifts and shapes sand into hill-like formations, which can sometimes rise as high as 150 metres.
• Most of the Thar Desert lies within India, spreading across the states of Rajasthan, Gujarat, Punjab, and Haryana.
• The desert acts as a natural barrier because its harsh conditions—very high daytime temperatures, cold nights, and lack of access to water—deter the movement of humans and animals.
• People living in the Thar have adapted their food habits, clothing, and lifestyle to suit the harsh desert conditions and the resources available there.

The Aravalli Hills

• The Aravallis are among the oldest mountains in the world, about 2.5 billion years old, and the range has many peaks and ridges.
• Its highest peak, Mount Abu, rises over 1,700 metres, while most of its hills are between 300 and 900 metres high.
• The Aravallis span the states of Delhi, Rajasthan, Haryana, and Gujarat, and a drive of about four and a half hours from Mount Abu to Jodhpur in the Thar Desert takes one into a completely different geography.
• The Aravallis play a vital role in shaping the geography and climate of northwestern India by acting as a natural barrier that prevents the Thar Desert from expanding further eastward.
• The range is rich in minerals such as marble, granite, zinc, and copper, and has supported mining and construction activities for centuries.
• Evidence from ancient mines at Zawar shows that, over eight centuries ago, Indians were the first in the world to master the delicate process of extracting zinc.
• Historic forts such as Chittorgarh, Kumbhalgarh, and Ranthambore are located in the Aravalli region.

The Peninsular Plateau

• A plateau is a landform that rises above the surrounding land and has a more or less flat surface, with some sides often forming steep slopes.
• India has several plateaus, and the most important is the triangular peninsular area in the middle and south of the country; it is also a very old land formation.
• Because this region is a peninsula, surrounded on three sides by the Arabian Sea, Bay of Bengal, and Indian Ocean, it is called the Peninsular Plateau.
• The plateau is bordered by two mountain ranges: the Western Ghats and the Eastern Ghats.
• The Western Ghats are taller and run along the western coast like a wall; during the monsoon season, many beautiful waterfalls flow down their steep sides.
• The Western Ghats have been declared a UNESCO World Heritage Site, are home to many rivers, and have rich biodiversity; their northern portion is also known as the Sahyadri Hills.
• The Eastern Ghats are lower and broken into smaller hills along the eastern coast.
• Between the two Ghats lies the Deccan Plateau, a vast area of flat highlands through which rivers such as the Godavari, Krishna, and Kaveri flow from west to east.
• These rivers are important for farming and provide water to millions of people.
• The plateau is rich in minerals, forests, and fertile land, making it vital for India’s economy.
• The Deccan Plateau tilts slightly to the east, so many rivers flow towards the Bay of Bengal; east-flowing rivers such as the Godavari, Krishna, and Mahanadi originate here and provide water for farming, industries, and hydroelectric power.
• West-flowing rivers such as the Narmada and Tapti also originate in this region and drain into the Arabian Sea.
• Dense forests on the plateau are home to tribal communities including the Santhal, Gond, Baiga, Bhil, and Korku, who have distinct languages, traditions, and ways of life closely connected to Nature.
• Tribal communities are largely spread across Jharkhand, West Bengal, Odisha, Assam, Madhya Pradesh, Chhattisgarh, Maharashtra, Telangana, and Gujarat.
• Plateaus have many beautiful waterfalls because rivers flow over their uneven and rocky surfaces; these waterfalls attract tourists, help generate hydroelectric power, and provide water for irrigation.

India’s Amazing Coastlines

• India’s coastline is dotted with beautiful beaches, rocky cliffs, and lush green forests; some beaches have golden sand, others have black rocks, some islands have coral reefs, and others are covered in thick jungles.
• The Indian coastline is over 7,500 km long and is full of natural variety and surprises.

West Coast of India:

• The West Coast of India stretches from Gujarat to Kerala, passing through Maharashtra, Goa, and Karnataka.
• Most rivers on the west coast originate in the Western Ghats, flow swiftly, and form estuaries.
• The coastline is shaped by alluvial deposits from short rivers and features coves, creeks, and estuaries; the Narmada and Tapti estuaries are the largest.
• The west coast has many important ports and cities, which have been centres of economic activity for millennia.

East Coast of India:

• The East Coast lies between the Eastern Ghats and the Bay of Bengal, stretching from the Ganga delta to Kanyakumari.
• It has wide plains and major river deltas, including the deltas of the Mahanadi, Godavari, Krishna, and Kaveri.
• Important water bodies such as Chilika Lake and Pulicat Lake are found here; a lagoon is a body of water separated from a larger body of water by a natural barrier.

Deltas:

• A delta is a landform formed at the mouth of a river when it deposits sediments into a larger body of water, such as an ocean, lake, or another river.
• Over time, these sediments build up and form a triangular or fan-shaped area.
• The Godavari, Krishna, Kaveri, and Mahanadi rivers create fertile deltas, making the land ideal for farming.

Indian Islands

• The Indian Islands are groups of islands scattered across the Indian Ocean, Arabian Sea, and Bay of Bengal, and they form part of India’s territory.
• India has two major island groups: Lakshadweep in the Arabian Sea and the Andaman and Nicobar Islands in the Bay of Bengal.
• These islands have unique wildlife, beautiful beaches, coral reefs, and volcanoes; several ancient tribes made these islands their home tens of thousands of years ago.

Lakshadweep Islands:

• Lakshadweep is an archipelago, meaning a group of islands, located in the Arabian Sea close to the Malabar coast of Kerala.
• It is made up of 36 coral islands, but not all of them are inhabited by people.
• India controls a vast marine area around these islands, which allows for fishing, resource exploration, and environmental protection.

Andaman and Nicobar Islands:

• The Andaman and Nicobar Islands form an archipelago of more than 500 large and small volcanic islands, divided into two distinct groups: the Andaman Islands and the Nicobar Islands.
• Their location is very important because they act like outposts of India, keeping watch over the ocean.
• The islands are home to a variety of flora and fauna.
• The Andaman Islands are historically significant because many freedom fighters were jailed under severe conditions in the prison complex called the Cellular Jail; it has been preserved to remind us of the sacrifices made by our forefathers for India’s freedom.

Barren Island:

• Barren Island in the Andaman and Nicobar Islands is the only active volcano in India.
• It sometimes erupts, sending smoke and lava into the sky.

The Delta in West Bengal and the Sundarbans

• Travelling back from the islands towards the eastern side of the Himalayas through the Bay of Bengal, we reach the Sundarbans.
• The Sundarbans are located in the delta of the Ganga, Brahmaputra, and their tributaries, where the river, sea, and land combine in a unique way.
• About half of the Sundarbans lies in India, while the rest lies in Bangladesh.
• The Sundarbans are a UNESCO Heritage Site and are home to many species, including the Royal Bengal Tiger.

The Hills of the Northeast

• Moving towards the hills of the Northeast, we reach the Garo, Khasi, and Jaintia Hills, which are part of the Meghalaya Plateau.
• These hills are known for their lush greenery, heavy rainfall, and breathtaking waterfalls.
• The region experiences one of the highest rainfalls in the world, making it rich in forests, unique wildlife, and fertile land.
• Mawlynnong Village, located in the East Khasi Hills of Meghalaya, is renowned as the ‘cleanest village in Asia’.
• The village is famous for its well-maintained cleanliness, bamboo dustbins, and eco-friendly living practices.
• Mawlynnong is also known for its living root bridges, created by weaving tree roots over many years.