📘 Chapter 3: Physiography and Drainage
🔷 Notes
🌍 India – Physiographic Divisions
- The Himalayas
- Young fold mountains from Pamir Knot to Arunachal Pradesh
- Subdivided into: Siwalik (youngest), Lesser Himalayas, Greater Himalayas (Himadri), Trans-Himalayas
- The North Indian Plains
- Flat, fertile land between Himalayas and Peninsula
- Formed by Ganga, Brahmaputra, Indus
- Subdivided into: Ganga Plains, Punjab Plains, Sunderban Delta, Thar Desert (Marusthali)
- The Peninsula
- Ancient, stable landmass with hill ranges and plateaus
- Includes: Aravali, Vindhya, Satpura, Deccan Plateau, Malwa, Bundelkhand, Chhota Nagpur
- The Coastal Plains
- Western Coast: Rocky, estuaries
- Eastern Coast: Deltaic, wide
- The Islands
- Andaman & Nicobar: Volcanic origin (e.g., Barren Island)
- Lakshadweep: Coral atolls in Arabian Sea
🌎 Brazil – Physiographic Divisions
- Highlands
- Brazilian & Guyana Highlands form South America’s core
- Highest peak: Pico da Neblina (3014 m)
- Rivers form rapids and waterfalls
- Great Escarpment
- Steep slope from Sao Paulo to Porto Alegre
- Causes rain shadow in northeast (Drought Quadrilateral)
- Coasts
- Northern Coast: Amazon mouth, Marajo Island
- Eastern Coast: São Francisco River, Praia do Cassino (longest beach)
- Plains
- Amazon Basin: Dense forest, inaccessible
- Pantanal: Swampy wetland in southwest
- Islands
- Coastal islands (depositional)
- Marine islands (coral, rocky)
🌊 Drainage Systems
India
- Himalayan Rivers (Perennial): Ganga, Yamuna, Brahmaputra
- Peninsular Rivers (Seasonal): Godavari, Krishna, Kaveri, Mahanadi, Narmada, Tapi
- Western Ghats as water divide
- West-flowing rivers: Luni, Sabarmati, Mahi
Brazil
- Amazon Basin: Largest river, high discharge, no delta
- Paraguay-Paraná system: Southwest Brazil
- São Francisco: Eastern Brazil
- Short coastal rivers: Important for populated areas
📝 Textbook Exercise – Solved
🔹 Q1. Complete the sentences:
- (a) Brazil is covered mainly by — (i) Highlands
- (b) Like Brazil, India too has — (ii) Ancient plateau
- (c) The Amazon Basin is mainly — (iii) Covered by dense forests
- (d) Amazon is a large river in the world. Near its mouth — (ii) No deltas are found
- (e) The Lakshadweep Islands of Arabian Sea are — (ii) Coral islands
- (f) To the foothills of the Aravalis — (ii) Lies the Mewad Plateau
🔹 Q2. Answer the following:
(a) Differentiate between the physiography of Brazil and India:
| Feature | India | Brazil |
|---|---|---|
| Mountains | Himalayas (young, high) | No long, high mountain ranges |
| Plateaus | Deccan Plateau | Brazilian & Guyana Highlands |
| Plains | Ganga-Brahmaputra | Amazon and Pantanal |
| Coastal Area | Deltaic East, Rocky West | Long, sandy, narrow |
| Wetlands | Sundarbans | Pantanal |
(b) Measures to control river pollution in India:
- Namami Gange project
- Sewage treatment plants
- Strict regulation of industrial discharge
- Eco-friendly practices during festivals
- Awareness campaigns
(c) Characteristics of North Indian Plains:
- Flat, low-lying
- Alluvial soil – fertile
- Dense population
- Flood-prone
- Eastward slope
(d) Reasons behind swamps in Pantanal:
- Low elevation
- Heavy rainfall
- Poor drainage
- Flat terrain and water stagnation
(e) Major water divides of India:
- Western Ghats: Arabian vs Bay of Bengal
- Vindhya-Satpura: Narmada vs Godavari
- Himalayas: Indus vs Ganga-Brahmaputra
🔹 Q3. Write Notes:
(a) Amazon River Basin: World's largest, dense forests, navigable, no delta, originates in Andes
(b) Himalayas: Young fold mountains, barrier in north, source of rivers, Himadri-Himachal-Siwalik
(c) Coasts of Brazil: 7400 km, North & East Atlantic, Marajo Island, Praia do Cassino
(d) Indian Peninsula: Ancient landmass, rich minerals, surrounded by Ghats, plateaus
(e) Great Escarpment: Steep edge of Brazilian Highlands, affects climate, causes rain shadow
🔹 Q4. Geographical Reasons:
- (a) No west-flowing rivers in Brazil — Slope is eastward to Atlantic
- (b) Indian coasts differ — Eastern is deltaic; western is rocky and narrow
- (c) Few ports on east coast — Gentle slope, delta formation, shallow waters
- (d) Ganga pollution affects more — Flows through populated, industrial areas
🔹 Q5. Identify the correct group:
- (a) NW to SE physiographic order in Brazil: (ii) Guyana Highlands – Amazon basin – Brazilian Highlands
- (b) North-flowing rivers in Brazil: (ii) Negro – Branco – Paru
✍️ 10 Sentences on Physiography
📌 India
- Five physiographic divisions exist.
- Himalayas are young fold mountains.
- Ganga-Brahmaputra plains are fertile.
- Deccan Plateau is ancient.
- Aravalis are oldest.
- Western Ghats form a divide.
- Eastern coast is deltaic.
- Western coast is rocky.
- Andamans are volcanic.
- Peninsula slopes eastward.
🌎 Brazil
- Highlands cover most of Brazil.
- Amazon basin is largest plain.
- Guyana and Brazilian shields are old.
- Coastal plains are narrow.
- Great Escarpment influences rainfall.
- No tall mountain ranges.
- Pantanal is largest wetland.
- Praia do Cassino is longest beach.
- Amazon has no delta.
- Coral and marine islands exist.