Karnataka Geography: Physical Features, Divisions, Rivers, and Climate
Introduction
Karnataka, situated in the southwestern region of India, spans an area of approximately 1,91,791 sq km — making it the eighth largest state by area. It lies between 11°5’N and 18°45’N latitude and 74°E and 78°5’E longitude. The state is bounded by Maharashtra and Goa to the north, Andhra Pradesh to the east, Tamil Nadu to the southeast, Kerala to the south, and the Arabian Sea to the west. The state’s diversity in physical features ranges from the towering Western Ghats to the flat Deccan plateau and the coastal lowlands.
Physical Divisions of Karnataka
Karnataka can be divided into four major physiographic divisions:
1. The Coastal Plain (Kanara Coastal Region)
- Also known as the Malenadu (land of forests and rain)
- Stretches along the Arabian Sea for about 320 km
- Comprises the districts of Dakshina Kannada, Udupi, and Uttara Kannada
- Maximum width of 65 km near Mangalore
- Characterized by sand dunes, lagoons, backwaters, and creeks
- Key ports: Mangalore (New Mangalore Port), Malpe, Bhatkal
- The Netravati and Swarna rivers flow through this region
2. The Western Ghats (Sahyadri Range)
- Running parallel to the coast, roughly 80–120 km inland
- Average elevation: 600–900 metres; highest peak: Mullayanagiri (1,930 m) in Chikkamagaluru district
- Known as the “Ghost of the Mountains” in local folklore
- Forms a natural barrier causing orographic rainfall
- Rich biodiversity — part of the Western Ghats biodiversity hotspot (UNESCO World Heritage Site)
- Major passes: Sampige, Ambutirtha, and Konkan
- Important hill stations: Kodagu (Coorg), Chikkamagaluru, Mangalore
3. The Central Plateau (Malnadu)
- The core of the Deccan Plateau lies in central Karnataka
- Comprises districts like Hassan, Chikkamagaluru, Shivamogga, Davanagere
- Undulating terrain with granite hills and laterite plateaus
- Key rivers: Tungabhadra, Kaveri, Hemavathi
- Coffee plantations extensively cultivated here — Chikkamagaluru is the birthplace of coffee in India (1847)
4. The Eastern Plains (Bayaluseeme)
- The dry, flat plateau region extending into the northeastern part
- Comprises districts: Kalaburagi, Yadgir, Raichur, Koppal, Bellary (Ballari)
- Average elevation: 300–600 metres
- Characterized by black cotton soil (vertisols) — highly suitable for cotton, jowar, sunflower
- Semi-arid climate with scanty rainfall
- The Krishna and Tungabhadra rivers are major lifelines here
Major Rivers of Karnataka
Karnataka is drained by several rivers belonging to the Krishna, Kaveri, and West-flowing river systems.
Krishna River System
| River | Origin | Key Dam | Notable Fact |
|---|---|---|---|
| Krishna | Mahabaleshwar (Maharashtra) | Almatti Dam (largest in Karnataka) | Flows through 11 districts |
| Tungabhadra | Varaha (Western Ghats) | Tungabhadra Dam, Hospet | Joint project with Andhra Pradesh |
| Bhima | Bhima peaks, Maharashtra | Bhima Dam, Yadgir | Inter-state river with major irrigation projects |
| Koyna | Western Ghats | Koyna Dam (Maharashtra border) | Known for Koyna Wildlife Sanctuary |
Almatti Dam on the Krishna River is the largest hydroelectric project in Karnataka with a capacity of 290 MW. The Upper Krishna Project involves the Almatti, Narayanpur, and Bijapur dam complexes.
Kaveri River System
- River Kaveri (Cauvery): Originates at Talacauvery in Coorg (Kodagu district) — a sacred pilgrimage site
- Flows through Chikkamagaluru, Hassan, Mandya, Mysore, Tiruchirapalli (Tamil Nadu)
- Known as the “Ganga of the South”
- Major tributaries: Hemavathi, Lakshmanathirtha, Kabini, Shimsha
- KRS (Krishnarajasagara) Dam built at Kannambadi (Mandya) — built in 1924 under the leadership of Sir M. Visvesvaraya
- Raft racing is popular in Kodagu’s Kaveri tributaries during monsoons
- water-sharing dispute with Tamil Nadu — governed by Kaveri Water Disputes Tribunal (1956)
West-Flowing Rivers (Into Arabian Sea)
- Netravati: Flows through Mangalore; participates in the port city’s irrigation
- Sharavathi: Originates near Ambuthirtha; forms the Jog Falls (Kunchika Falls) — 830 ft, 2nd highest waterfall in India after Nohsngith in Meghalaya
- Kundapur: Coastal river in Udupi district
- Mahi: Minor river in Dakshina Kannada
East-Flowing Rivers (Into Bay of Bengal)
- Penna, Papagni, and Pinder rivers flow into Andhra Pradesh
- Contribute to inter-state river water sharing
Climate of Karnataka
Karnataka exhibits three distinct climatic zones:
1. Coastal Climate (Hot and Humid)
- Temperature: 22°C–34°C year-round
- Rainfall: 3,000–4,000 mm per year (heavy monsoonal)
- Active from June to September (Southwest Monsoon)
- Tropical evergreen forests dominate
- Mangalore records some of the highest humidity in India
2. Ghat Region (Cold and Wet)
- Temperature: 15°C–28°C (coolest part of Karnataka)
- Rainfall: 2,500–5,000 mm (highly orographic)
- Kodagu, Chikkamagaluru, and parts of Shivamogga district
- Snowfall occasionally in higher peaks of Kuduremukha and Mullayanagiri
- Major coffee-growing belt due to moderate temperatures and adequate rainfall
3. Interior Plateau (Hot and Dry)
- Temperature: 18°C–40°C (extreme summer heat)
- Rainfall: 500–900 mm (scanty and uncertain)
- Semi-arid conditions prevail
- North Karnataka districts (Kalaburagi, Yadgir, Koppal) face drought conditions frequently
- Dryland farming predominates — jowar, bajra, cotton, sunflower
Monsoon Pattern
- Southwest Monsoon (June–September): Primary rainfall contributor, accounting for ~80% of annual rainfall
- Northeast Monsoon (October–November): Secondary rainfall, important for Rabi crops
- Retreating monsoon brings light rainfall to coastal and southern interior during October
Soils of Karnataka
| Soil Type | Region | Crops Grown |
|---|---|---|
| Black Cotton Soil (Vertisols) | North Karnataka (Kalaburagi, Yadgir, Bellary) | Cotton, jowar, sunflower |
| Red Loamy Soil | Southern and Eastern Karnataka | Ragi, rice, sugarcane |
| Laterite Soil | Western Ghats and Malnadu | Coffee, rubber, spices |
| Sandy Loam | Coastal region | Cashew, coconut, arecanut |
| Alluvial Soil | River valleys (Krishna, Kaveri, Tungabhadra) | Paddy, sugarcane, vegetables |
Important Facts for KPSC KAS Exam
- Karnataka contributes approximately 75% of India’s coffee production (Arabica and Robusta varieties)
- The state has 10 agro-climatic zones — among the most diverse in India
- Mullayanagiri (1,930 m) is the highest peak in Karnataka and the entire Western Ghats south of the Himalayas
- Jog Falls (Sharavathi River) is the 2nd highest waterfall in India after Nohsngith
- Kuduremukha is a UNESCO World Heritage site within the Western Ghats
- Karnataka receives average annual rainfall of 1,248 mm
- The causality ratio of the Krishna River basin is 1:5.7 (runoff vs. precipitation)
- Mysore sits in the thermally quiet zone and is relatively earthquake-free
Conclusion
Karnataka’s geography is a remarkable blend of mountains, plateaus, coasts, and river valleys. Understanding its physical divisions and river systems is crucial for comprehending the state’s agriculture, climate, and socioeconomic patterns. For the KPSC KAS exam, focus on identifying districts associated with each physiographic division, major dams and rivers, rainfall distribution patterns, and the agricultural implications of each soil type.