Physical Features Of India (Basic)

Northern Hemisphere Dominance:

India lies entirely in the Northern Hemisphere. Its mainland extends from the Tropic of Cancer ($23^\circ30'N$) which divides the country into roughly two equal halves.

Latitudinal Extent:

The latitudinal extent of India is approximately $37^\circ6'N$ to $8^\circ4'N$. The southern tip of the mainland, Kanyakumari, lies near the equator, while the northernmost point in Jammu and Kashmir (now Ladakh) extends towards the temperate latitudes.

The latitudinal extent from the equator means that the southern parts of India experience a relatively uniform, tropical climate with less variation in day and night lengths throughout the year. As one moves northwards, the influence of latitude becomes more pronounced, leading to greater seasonal variations in temperature and day length, characteristic of a subtropical to temperate climate.

Longitudinal Extent:

India's longitudinal extent is from $68^\circ7'E$ to $97^\circ25'E$. This considerable east-west span of approximately $30^\circ$ results in a significant difference in local time between the westernmost part (Gujarat) and the easternmost part (Arunachal Pradesh).

To standardize time across the country and avoid confusion in communication, railway timings, and other sectors, India observes a standard time based on a specific meridian. The Indian Standard Meridian (ISM) passes through $82^\circ30'E$ longitude, which runs through Mirzapur in Uttar Pradesh. This meridian is 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT), often denoted as IST (Indian Standard Time).

The difference in local time between the extreme east and west can be as much as two hours. For instance, sunrise occurs about two hours earlier in Arunachal Pradesh than in Gujarat.

Key Geographical Points:

• The southernmost point of the Indian Union, including its territories, is Indira Point, located in the Andaman and Nicobar Islands, at $6^\circ45'N$ latitude.
• The southernmost point of the mainland is Kanyakumari, at $8^\circ4'N$ latitude.
• The westernmost point of India is near Ghuar Moti in Gujarat, at $68^\circ7'E$ longitude.
• The easternmost point of India is near Kibithu in Arunachal Pradesh, at $97^\circ25'E$ longitude.

The strategic location of India in the Indian Ocean is also crucial, providing it with a dominant position in maritime trade routes connecting Europe, West Asia, Africa, and Southeast Asia.

Total Area:

India's total area is approximately 3.28 million square kilometers ($3,287,263 \, km^2$). This vast area accounts for about 2.4% of the total geographical area of the world.

Land Boundary and Coastline:

• India possesses an extensive land boundary measuring about 15,200 kilometers. This boundary connects it with numerous countries, influencing its geopolitical relations and trade.
• The coastline of the mainland of India stretches for about 6,100 kilometers. This long coastline borders the Arabian Sea to the west, the Indian Ocean to the south, and the Bay of Bengal to the east, facilitating maritime trade and providing access to numerous ports.
• Including the island territories of Andaman and Nicobar Islands and Lakshadweep, the total coastline length increases significantly to about 7,516.6 kilometers. This highlights the extensive maritime influence and potential for India.

Comparative Size:

To understand India's size, it's useful to compare it with other major countries:

This significant area allows for a wide range of geographical features, climatic conditions, and resource distribution within the country.

Formation and Structure:

The Himalayas were formed by the collision of the Indian tectonic plate with the Eurasian tectonic plate, a process that began approximately 50 million years ago. This ongoing collision continues to uplift the mountains, making them geologically active with seismic activity.

The Himalayan mountain range can be divided into three parallel ranges:

• The Great Himalayas (Himadri): This is the northernmost and most continuous range, containing the loftiest peaks, averaging about 6,000 metres in height. It is largely composed of granite and is perennially snow-bound. Peaks like Mount Everest (8,848.86 m), Kanchenjunga, and Makalu are located here.
• The Lesser Himalayas (Himachal): Situated south of the Himadri, this range is composed of highly compressed and altered rocks. The altitudes vary between 3,700 and 4,500 metres. This range is known for its popular hill stations like Shimla, Kullu, Manali, and Nainital, and its valleys like the Kangra and Kullu valleys.
• The Shiwalik: The southernmost range, also known as the Outer Himalayas, extending from Jammu and Kashmir to Arunachal Pradesh. It is the youngest range and is composed of unconsolidated river alluvium brought down from the main Himalayan ranges. Its altitude varies between 900 and 1100 metres. The longitudinal valleys (duns), like Dehradun, Kotah, and Patli Dun, lie between the Lesser Himalayas and the Shiwaliks.

Geographical Significance:

• Climate Barrier: The Himalayas act as a barrier, preventing the cold Siberian winds from entering India during winter and influencing the monsoon patterns by obstructing the summer monsoon clouds.
• Source of Rivers: They are the source of major perennial rivers like the Ganga, Yamuna, Brahmaputra, Indus, Sutlej, and Beas, providing water for irrigation and power generation.
• Biodiversity Hotspot: The varied altitudes and climatic conditions support diverse ecosystems and a rich variety of flora and fauna.
• Natural Defence: They provide a natural defence against invasions from the north.

Derivation of Formation: The formation of the Himalayas is explained by the Theory of Plate Tectonics. India, part of the Indo-Australian plate, moved northwards and collided with the Eurasian plate. The immense pressure from this collision caused the crust to fold and fault, uplifting the sediments that had accumulated in the Tethys Sea (an ancient ocean basin between the two plates) to form the towering mountain ranges.

Formation:

These plains have been formed over millions of years by the deposition of silt, sand, clay, and gravel carried down by the Himalayan rivers from the northern mountains. The deposition process created a vast, flat, and fertile alluvial plain.

Formation Process:

1. Depositional Activity: Rivers carry eroded material from the Himalayas. As the rivers descend from the mountains onto the plains, their speed decreases, causing them to deposit their sediment load.
2. Alluvial Fan Formation: Rivers deposit heavier materials like boulders and pebbles at the foothills, forming a wide alluvial fan.
3. River Meandering: On the plains, rivers tend to meander, forming ox-bow lakes and floodplains.
4. Delta Formation: As the rivers approach the sea, they often form deltas, which are highly fertile depositional landforms.

Area and Extent:

The Northern Plain covers an area of about 7 lakh square kilometers. It is approximately 2,400 km long and 240 to 320 km broad, stretching from the Indus river system in the west to the Brahmaputra river system in the east.

Divisions of the Northern Plain:

Based on the relief features and soil characteristics, the Northern Plain is often divided into four regions:

• Bhabar: This is a narrow belt, about 8-10 km wide, lying at the foothills of the Shiwaliks. Here, rivers deposit their load in the form of coarse and alluvial fans. Many streams disappear into the Bhabar, reappearing in the Terai region.
• Terai: South of the Bhabar, this is a region of marshy and wet land. It is characterized by dense forests and a variety of wildlife. Streams and rivers reappear in this belt and form marshy land.
• Bhangar: This is the largest part of the Northern Plain, formed by older alluvium. It lies above the flood plains of the rivers and is characterized by terraces. The soil in this region contains calcareous deposits locally known as kankar.
• Khadar: This region consists of newer, younger alluvium deposits. It is found in the floodplains of the rivers and is frequently flooded by the rivers during the monsoon. The Khadar is very fertile and ideal for intensive agriculture.

Significance:

• Agriculture: The fertile alluvial soil and abundant water supply make it India's granary, supporting major crops like wheat, rice, sugarcane, and pulses.
• Population Density: It is one of the most densely populated regions in the world due to its agricultural productivity and the presence of major river valleys.
• Connectivity: It serves as a major transportation and communication corridor for the country.

Formation:

The plateau is part of the oldest landmass, the Gondwanaland. It was formed due to the breaking and drifting of the Gondwana landmass, making its rocks very old and highly metamorphosed.

General Characteristics:

• It is roughly triangular in shape, with its base in the north and apex pointing southwards towards the Indian Ocean.
• It is bordered by the Aravalli Hills in the northwest, the Rajmahal Hills in the east, the Garo, Khasi, and Jayantiya Hills in the east, and the Cardamom Hills in the south.
• The plateau is characterized by a series of raised plateaus and valleys.
• It contains rich mineral deposits, including iron ore, coal, bauxite, copper, etc.

Major Divisions:

The Peninsular Plateau is broadly divided into two main divisions:

• The Central Highlands:
  • This part lies to the north of the Narmada river, covering a major part of the Malwa plateau.
  • It is bounded by the Aravalli Range in the northwest and the Vindhyan range in the south.
  • The rivers flowing here, like the Chambal, Sindh, Betwa, and Ken, are tributaries of the Yamuna.
  • The Chota Nagpur plateau in the east, forming the latter part of the central highlands, is rich in mineral resources, especially coal and iron ore.
• The Deccan Plateau:
  • This is a triangular landmass lying to the south of the Narmada river.
  • It is bordered by the Satpura range in the north, the Western Ghats in the west, and the Eastern Ghats in the east.
  • The plateau is higher in the west and slopes gently eastwards, evidenced by the drainage of its rivers (Godavari, Krishna, Kaveri) towards the Bay of Bengal.
  • The Western Ghats are a more continuous range, while the Eastern Ghats are discontinuous and broken.

Significance:

• Mineral Resources: It is a repository of valuable minerals, supporting India's industrial sector.
• River Systems: It forms the source of major peninsular rivers, vital for irrigation and hydropower.
• Agriculture: Parts of the plateau, especially the river valleys, are fertile and support agriculture.

Formation and Climate:

The desert is believed to have been an ancient sea bed. It receives very low rainfall, generally less than 150 mm per year, and experiences extreme temperatures and low humidity. The region is characterized by arid landforms.

Features:

• Sand Dunes: The most prominent features are undulating topography, sand dunes, and rocky plains. Large areas are covered with sand.
• Barchans: Crescent-shaped sand dunes that shift with the wind are common.
• Rocky Outcrops: Some areas have isolated rocky hills.
• Vegetation: Vegetation cover is sparse and consists mainly of thorny bushes, grasses, and hardy trees adapted to arid conditions.
• Luni River: The only significant river in this region, the Luni, flows through the southern part of the plateau and disappears into the Rann of Kachchh.

Significance:

• It plays a role in regional weather patterns.
• It supports a unique ecosystem of flora and fauna adapted to harsh conditions.
• Tourism and activities like camel safaris are significant.

Western Coastal Plain:

This plain lies between the Western Ghats and the Arabian Sea. It is a narrower strip compared to the eastern coast.

• Divisions: It is broadly divided into three sections:
  • The Northern Part (Konkan Coast): Extends from Maharashtra to Goa. It is a rugged coast with many inlets and bays.
  • The Central Part (Kannada Plain): Extends from Goa to Karnataka, characterized by features like estuaries and sand dunes.
  • The Southern Part (Malabar Coast): Extends from Karnataka to Kerala. It is known for its backwaters, lagoons, and palm-fringed beaches.
• Characteristics: It has several important ports like Mumbai and Kandla. It also features unique physiographic features like the backwaters of Kerala.

Eastern Coastal Plain:

This plain lies between the Eastern Ghats and the Bay of Bengal. It is wider than the western coastal plain and is formed by river deltas.

• Divisions: It is divided into two main parts:
  • The Northern Circar: Located between the Mahanadi and Krishna rivers, characterized by fertile deltas of major rivers like the Godavari and Krishna. It includes the Andhra Pradesh coast.
  • The Coromandel Coast: Located south of the Krishna river, down to Kanyakumari. It is known for the fertile delta of the Kaveri river.
• Characteristics: It has major ports like Chennai and Vishakhapatnam. The coastal plains are fertile due to riverine deposits, supporting extensive agriculture, especially rice cultivation.

Significance:

• Agriculture: The fertile deltas and plains are crucial for agriculture, particularly rice cultivation.
• Ports: They provide crucial locations for major ports facilitating international trade.
• Fisheries: The coastal waters support significant fishing activities.

Andaman and Nicobar Islands:

Located in the Bay of Bengal, these islands are an eastward extension of the submarine mountain range that emerged from the sea. They are believed to be the peaks of submerged mountains.

• Location: Situated off the eastern coast of India, extending from north to south.
• Geology: Primarily composed of sedimentary rocks and believed to be of volcanic origin in parts (e.g., Barren Island and Narcondam Island have active volcanoes).
• Structure: Divided into the Andaman group in the north and the Nicobar group in the south. The Indira Point, the southernmost point of India, is located in the Nicobar group.
• Climate: Equatorial climate with high humidity and temperature, and heavy rainfall.
• Vegetation: Dense tropical rainforests.
• Significance: Important for biodiversity, tourism, and strategic defence purposes.

Lakshadweep Islands:

Located in the Arabian Sea, these are a group of small islands, predominantly coral in origin.

• Location: Situated off the southwestern coast of India.
• Geology: Composed of coral polyps, forming coral islands. The main islands include Kavaratti (administrative headquarters), Agatti, and Minicoy.
• Structure: The islands are scattered over a large area.
• Climate: Tropical maritime climate with moderate temperatures and humidity.
• Vegetation: Coconut palms and some tropical flora.
• Significance: Important for tourism, fishing, and biodiversity, particularly marine life.