UDAAN Prelims Wallah: Indian Geography

• The UDAAN Prelims Wallah static series is designed for the 2025 prelims.
• It covers Indian geography, human and economic geography.
• It is presented as a quick and comprehensive revision series.

Second Edition Information

• Second edition is by Physicswallah Private Limited.
• ISBN: 978-93-6897-735-3
• Mobile application available on Play Store; Physics Wallah
• Website: https://www.pw.live;https://pwonlyias.com/
• Email: [email protected]

Overview

• This book aims to provide supreme-quality study material for UPSC students.
• It is designed for easy understanding, with guidance and supervision from faculties.
• The material promotes conceptual and fun-based learning with exam-oriented content.
• It adopts a multi-faceted approach to mastering concepts for the competitive exam.
• The study material is short, crisp, concise, and of high quality.

Book features

• Holistic coverage of topics, strictly as per exam syllabus
• One-stop solution for prelims based, subject-wise coverage.
• Diagrams and timelines for quick understanding and revision.
• Quick revision module for the UPSC prelims examination.
• Every topic is structured in headings and bullets for easy understanding of the students.

UPSC Foundation and Optional Courses

• ONLYIAS by Physics Wallah offers UPSC foundation and optional courses.

Course Details

• SANKALP 2026: Hinglish / हिन्दी
• PRAHAR 2025: Hinglish / हिन्दी
• TITAN 2026 / 2025: English
• UPSC OPTIONAL COURSE 2025: Hinglish / हिन्दी

Optional Subjects

• Anthropology
• PSIR
• History
• Sociology
• Geography
• Public Administration
• Mathematics
• हिन्दी साहित्य

Table of contents

• India-Location, Structure and Physiography
• Drainage System
• Climate
• Natural Hazards and Disasters
• Soils and Natural Vegetation
• Resources and Manufacturing Industries
• Trade, Transport and Communication
• Population and Settlements

India's Geography Overview

• India covers an area of 3.28 million sq. km, which is 2.4% of the world's total area.
• Its coastline is 6,100 km along the mainland and 7,517 km including island groups.
• India has the longest coastline among Indian Ocean littoral countries.
• Territorial waters extend 12 nautical miles (22.2 km) from the coast.

Geographical extent

• Latitudinal Extent: Ranges from 6°8′N (Kanyakumari) to 37°6′N (Ladakh), approximately 3,200 km.
• Longitudinal Extent: Extends from 68°7'E (Gujarat) to 97°25′E (Arunachal Pradesh), covering about 2,900 km.

Key geographic features

• Southernmost Mainland Point is Kanyakumari.
• Northernmost Point is Indira Col in the Karakoram Range.
• Southernmost Point in the Indian Union is Indira Point, which was submerged in 2004 tsunami, located in the Great Nicobar Islands.
• It is separated from Indonesia by the Six Degree Channel.

Neighboring countries

• Land Neighbors: India shares borders with Pakistan and Afghanistan to the northwest; China, Nepal, and Bhutan to the north; and Myanmar and Bangladesh to the east.
• Island Neighbors: Sri Lanka (separated by the Gulf of Mannar and Palk Strait) and Maldives (separated from Lakshadweep by the Eight Degree Channel).

Significant latitudes and longitudes

• Tropic of Cancer (23°27'N): Passes through eight states Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, and Mizoram.
• Maximum passage is through Madhya Pradesh, while Rajasthan has the shortest section; the Mahi River crosses it twice.
• Capital cities nearby are Ranchi (Jharkhand), Jaipur (Rajasthan), Agartala (Tripura), and Aizawl (Mizoram), with Agartala closest to the Tropic of Cancer.

Standard meridian

• Standard Meridian of India (82°30′E): Defines the Indian Standard Time (IST), ensuring uniform time.
• It crosses Uttar Pradesh (Mirzapur), Chhattisgarh, Odisha, Madhya Pradesh and Andhra Pradesh, with Raipur (Chhattisgarh) being the capital city closest to this meridian.
• Climatic Zone: Tropic of Cancer divides into Tropical Zone (south, warmer climate) and Subtropical Zone (north, varied temperatures).

Structure and Physiography

• Indian plate fragmented and shifted northwards from south of equator to current location
• Geological divisions of India include the Himalayas, Indo-Ganga-Brahmaputra Plain, the Peninsular Block, the Indian Desert, the Coastal Plains, and the Islands.

The Himalayas

• Formed by the collision of Indian and Eurasian tectonic plates.
• Ranges: Outer Himalayas (Siwaliks), Lesser Himalayas (Himachal), and Greater Himalayas (Himadri).
• Source of major rivers like the Indus, Ganges, and Brahmaputra.

Indo-Ganga-Brahmaputra Plain

• A geo-synclinal depression gradually filled with alluvial deposits from the Indus, Ganga and Brahmaputra rivers.

The Peninsular Block

• Northern Boundary: Irregular line extending from Kachchh to the Rajmahal Hills and the Ganga delta.
• Composed mainly of ancient gneisses and granites.
• Oldest physiographic feature, stable since Cambrian period.
• Includes rift valleys like the Narmada, Tapi, and Mahanadi.
• Mountain ranges: Aravali, Nallamala, Javadi, Veliconda, Palkonda, and Mahendragiri.

Division of Himalayas

• North-South: Great Himalayas (Inner), Lesser Himalayas (Middle), Shiwaliks (Outer).
• East-West: Kashmir or Northwestern Himalayas, Himachal and Uttarakhand Himalayas.
• Nepal Himalayas: Mahabharat, Churia Ranges.
• Darjeeling and Sikkim Himalayas: Kangchenjunga, Mahabharat Range.
• Arunachal Himalayas: Patkai Bum, Naga Hills, Abor Hills.

Purvanchal Hills

• Patkai Bum: Border between Arunachal Pradesh and Myanmar.
• Naga Hills: Act as a watershed between India and Myanmar.
• Manipur Hills: Southward extension of Naga Hills.
• Mizo Hills (Lushai): Known for tribal populations and Jhum cultivation.

Important Himalayan glaciers

• Siachen (Karakoram)- largest in Nubra Valley, second longest outside polar region
• Gangotri (Uttarakhand)- origin below Chaukhamba peak, known as 'Gomukh.'

Northern plains of India

• Formed by Indus, Ganga, Brahmaputra; fertile alluvial soil, elevation 50-150 m.
• Divisions include the Western Part (Punjab Plains, dominated by doabs), Central Part (Ganga Plains, fertile area), and the Eastern Part (Brahmaputra Plains, with riverine islands.)
• Deltaic Features: The mouths of these rivers form large deltas; Sundarbans Delta, the largest, is formed by Ganges and Brahmaputra.
• North-South Division: Bhaba