Class 9 Geography Notes: Physical Features of India
Class 9 Geography Notes: Physical Features of India
Welcome back! Today we are tackling Class 9 Geography Chapter 2: Physical Features of India.
India is a vast country with varied landforms. Think of it as a massive geographical buffet—we have towering mountains, flat plains, dry deserts, and beautiful islands. Our country's physical features were formed over millions of years due to various geological processes, including the shifting of tectonic plates.
Let’s break down the six major physiographic divisions of India into simple, bite-sized notes that are perfect for exam revision!
1. The Himalayan Mountains: The Mighty Wall of the North
The Himalayas are young, fold mountains that run along the northern borders of India. They form an arc, covering a distance of about 2,400 km.
The Himalayas consist of three parallel ranges in their longitudinal extent:
The Great or Inner Himalayas (Himadri): This is the northernmost range and the most continuous one. It contains the loftiest peaks with an average height of 6,000 meters. (Fun fact: Mount Everest is located here, though it's in Nepal!). It is perennially snow-bound.
The Lesser Himalayas (Himachal): Lying south of the Himadri, this range is mainly composed of highly compressed and altered rocks. The altitude varies between 3,700 and 4,500 meters. This region is famous for its beautiful hill stations like Kashmir, Kangra, and Kullu valleys.
The Shiwaliks: This is the outermost range of the Himalayas. They have an average width of 10-50 km and an altitude varying between 900 and 1,100 meters. They are made of unconsolidated sediments brought down by rivers.
(Exam Tip: The longitudinal valleys lying between the Lesser Himalayas and the Shiwaliks are known as "Duns" – like Dehradun and Kotlidun!)
2. The Northern Plains: The Food Bowl of India
South of the Himalayas lies the massive Northern Plain. It was formed by the interplay of three major river systems: the Indus, the Ganga, and the Brahmaputra, along with their tributaries.
Soil: It is formed entirely of extremely fertile alluvial soil.
Size: It spreads over an area of 7 lakh square kilometers and is about 2,400 km long.
Significance: Because of the fertile soil, adequate water supply, and favorable climate, it is a very densely populated region and agriculturally the most productive part of India.
The plains can be divided into four distinct relief regions from North to South:
Bhabar: A narrow belt of pebbles lying parallel to the slopes of the Shiwaliks. Rivers disappear in this zone.
Terai: A wet, swampy, and marshy region south of Bhabar where rivers re-emerge. (Historically full of thick forests and wildlife).
Bhangar: The largest part of the northern plain formed of older alluvium soil. It lies above the floodplains and presents a terrace-like feature.
Khadar: The newer, younger deposits of the floodplains. They are renewed almost every year, making them highly fertile and ideal for intensive agriculture.
3. The Peninsular Plateau: The Ancient Landmass
The Peninsular Plateau is a tableland composed of old crystalline, igneous, and metamorphic rocks. It was formed due to the breaking and drifting of the ancient Gondwana land, making it the oldest landmass in India.
It has two broad divisions:
The Central Highlands: Lies north of the Narmada river covering a major area of the Malwa plateau. The Vindhya range bounds it on the south and the Aravalis on the northwest.
The Deccan Plateau: A triangular landmass lying south of the Narmada river.
The Ghats (The Edges of the Deccan Plateau):
Western Ghats: They mark the western edge. They are continuous and can be crossed through passes only. They are higher (average elevation 900-1600 meters) and cause orographic rain by facing the rain-bearing winds. Anaimudi is the highest peak here.
Eastern Ghats: They mark the eastern edge. They are discontinuous, irregular, and dissected by rivers draining into the Bay of Bengal. Their average elevation is lower (600 meters). Mahendragiri is the highest peak.
4. The Indian Desert: The Arid West
The Indian Desert (Thar Desert) lies towards the western margins of the Aravali Hills.
Landscape: It is an undulating sandy plain covered with sand dunes. Crescent-shaped dunes called Barchans cover larger areas.
Climate & Vegetation: It receives very low rainfall (below 150 mm per year). It has an arid climate and low vegetation cover.
Rivers: Streams appear during the rainy season but soon disappear into the sand. Luni is the only large river in this region.
5. The Coastal Plains: The Ocean Borders
The Peninsular Plateau is flanked by stretches of narrow coastal strips, running along the Arabian Sea on the west and the Bay of Bengal on the east.
The Western Coast: Sandwiched between the Western Ghats and the Arabian Sea, it is a narrow plain. It consists of three sections:
Konkan (Mumbai-Goa) in the north
Kannad Plain in the center
Malabar Coast in the south
The Eastern Coast: Along the Bay of Bengal, these plains are wide and level. It is divided into:
Northern Circar in the northern part
Coromandel Coast in the southern part
(Note: Large rivers like the Mahanadi, Godavari, Krishna, and Kaveri have formed extensive deltas on this coast.)
6. The Islands: Our Tropical Outposts
India has two major island groups:
Lakshadweep Islands: Located in the Arabian Sea, close to the Malabar coast of Kerala. They are small and composed of coral deposits. Kavaratti island is the administrative headquarters.
Andaman and Nicobar Islands: Located in the Bay of Bengal, extending from north to south. They are bigger in size, more numerous, and scattered. They are believed to be an elevated portion of submarine mountains. They hold great strategic importance and possess a huge diversity of flora and fauna.
Quick Revision Summary 📝
India has 6 physical divisions: Himalayas, Northern Plains, Peninsular Plateau, Indian Desert, Coastal Plains, and Islands.
The Himalayas are young fold mountains divided into Himadri, Himachal, and Shiwaliks.
The Northern Plains are extremely fertile (formed by Indus, Ganga, Brahmaputra).
The Peninsular Plateau is the oldest landmass, flanked by the Western and Eastern Ghats.
Lakshadweep islands are formed from corals; Andaman & Nicobar are elevated submarine mountains.
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