Rajasthan Koppen Climate Classification GK
PART - 11: Koppen's Climate Classification#
Detailed Index#
| Section |
Topic |
Exam Importance |
| 11.1 |
Conceptual Framework |
★★★★ |
| 11.2 |
Letter Code Decoding |
★★★★★ |
| 11.3 |
Four Zones of Rajasthan |
★★★★★ |
| 11.4 |
Detailed Zonal Analysis |
★★★★★ |
| 11.5 |
Limitations & Criticism |
★★★ |
| 11.6 |
Key Exam Pointers |
★★★★★ |
| 11.7 |
Comparative Study |
★★★★ |
📖 11.1 Conceptual Framework & Theory
The German-Russian meteorologist and geographer Dr. Wladimir Köppen presented the first systematic classification of world climate in 1900 (with subsequent revisions in 1918 and 1936).
| Basis of Classification |
Scientific Description |
| Primary Basis |
Natural Vegetation: Köppen believed that the vegetation of a region is the best natural indicator of its long-term climatic conditions. This theory is based on the vegetation belts of French botanist De Candolle. |
| Secondary Basis |
Monthly and annual average temperature and average monthly precipitation. |
| Methodology |
Empirical and descriptive classification, using coded letter symbols from the English alphabet. |
📖 11.2 Scientific Decoding of Köppen's Letter Codes
Köppen used a combination of capital and small letters to represent the climatic conditions of Rajasthan:
| Letter |
German/Technical Origin |
Scientific Meaning |
Context in Rajasthan |
| A |
Tropical |
Tropical humid climate (Avg temp of coldest month > 18°C) |
Southern Rajasthan (Banswara, Dungarpur, Jhalawar) |
| B |
Dry Climates |
Dry climate (Annual rainfall < PET) |
About 60% desert region west of Aravalli |
| C |
Warm Temperate |
Warm temperate climate (Coldest month temp between -3°C and 18°C) |
Eastern and south-eastern plains of Rajasthan |
| W |
Wüste (German) |
True Desert — extremely low rainfall (< 20 cm) |
Jaisalmer, Phalodi, western part of Bikaner |
| S |
Steppe (German) |
Semi-arid grassland (Semi-Arid Steppe) — rainfall 20-40 cm |
Shekhawati, Luni Basin, Bangar region |
| h |
heiss (German) |
Hot (Average annual temperature > 18°C) |
Applies to all arid regions of the state |
| w |
wintertrocken |
Dry Winter — most rainfall from summer monsoon |
Winter is generally dry throughout Rajasthan |
| g |
Gangetic |
Gangetic thermal pattern (Hottest month just before rainy season, i.e., May-June) |
Eastern plains of Rajasthan |
📖 11.3 Four Köppen Climatic Zones of Rajasthan
Köppen has divided Rajasthan mainly into 4 climatic zones:
| S.No. |
Climate Code |
Köppen's Name |
Representative District |
Avg Rainfall |
Natural Vegetation |
Major Extension Area |
| 1. |
BWhw |
Tropical Arid Desert Climate |
Bikaner |
10-20 cm |
Xerophytes |
Jaisalmer, Bikaner, Phalodi, Anupgarh, Western Barmer |
| 2. |
BShw |
Steppe Type |
Nagaur |
20-40 cm |
Steppe Type |
Sikar, Jhunjhunu, Churu, Nagaur, Jalore, Pali |
| 3. |
Cwg |
Gangetic |
Tonk |
60-80 cm |
Mixed Deciduous |
Jaipur, Dausa, Alwar, Bharatpur, Dholpur, Karauli |
| 4. |
Aw |
Savanna |
Dungarpur |
80-150 cm |
Dry Teak |
Banswara, Dungarpur, Pratapgarh, Jhalawar, Mount Abu |
📖 11.4 Detailed Zonal Analysis
1️⃣ BWhw Zone — Tropical Arid Desert Climate Zone#
This is the extreme western region of Rajasthan, where climatic conditions are extremely dry and harsh:
| Aspect |
Description |
| Code Meaning |
B = Dry, W = Desert, h = Hot (>18°C), w = Dry Winter |
| Representative District |
Bikaner |
| Extension Area |
Jaisalmer, Bikaner, Phalodi, Anupgarh, Jodhpur Rural (W), Barmer (NW), Sri Ganganagar (S) |
| Rainfall |
10-20 cm (Irregular, low, uncertain) |
| Temperature |
Summer: 45°C-50°C; Winter: 0°C-5°C |
| Vegetation |
Xerophytes |
| Main Species |
Phog, Kair, Lani, Thuhar, Aakda, Khejri, Sewan grass |
Steppe Type Climate Zone#
This is a transitional climatic belt located between the desert and the Aravalli.
| Aspect |
Description |
| Code Meaning |
B = Dry, S = Steppe, h = Hot, w = Dry Winter |
| Representative District |
Nagaur |
| Area |
Largest climatic zone of Rajasthan |
| Extension Area |
Sikar, Jhunjhunu, Churu, Nagaur, Didwana-Kuchaman, Pali, Jalore, Sanchore, Jodhpur |
| Rainfall |
20-40 cm |
| Temperature |
Summer: 38°C-42°C; Winter: Below 0°C (Fatehpur) |
| Vegetation |
Steppe Type |
| Main Species |
Rohida, Khejri, Ber, Babool, Dhaman, Karad grass |
Gangetic Climate Zone#
This is the most agriculturally productive and densely populated part of the state, located east of the Aravalli.
| Aspect |
Description |
| Code Meaning |
C = Warm Temperate, w = Dry Winter, g = Gangetic |
| Representative District |
Tonk |
| Extension Area |
Jaipur, Dausa, Alwar, Bharatpur, Dholpur, Karauli, Sawai Madhopur, Tonk, Ajmer, Bhilwara, Chittorgarh |
| Rainfall |
60-80 cm (by Purvaiya) |
| Temperature |
Summer: 34°C-40°C; Winter: 10°C-16°C |
| Vegetation |
Tropical Dry Deciduous |
| Main Species |
Dhokra, Salar, Khair, Dhak/Palash, Shisham, Neem, Baheda |
Savanna Climate Zone#
This is the extreme southern and south-eastern part of Rajasthan, where the state's maximum rainfall is recorded.
| Aspect |
Description |
| Code Meaning |
A = Tropical Humid, w = Dry Winter |
| Representative District |
Dungarpur |
| Extension Area |
Vagad (Banswara, Dungarpur, Pratapgarh), Hadoti (Jhalawar, Baran, S. Kota), Mount Abu |
| Rainfall |
80-100 cm+ (Mount Abu: 150 cm) |
| Temperature |
Summer: 30°C-35°C; Winter: 14°C-18°C |
| Vegetation |
Savanna & Dry Teak Forests |
| Main Species |
Teak, Bamboo, Mahua, Tendu, Mango, Jamun |
📖 11.5 Limitations & Criticism of Köppen's Classification
| Limitation |
Description |
| Too Vegetation-Centric |
Köppen considered vegetation as the sole determinant of climate, whereas local relief, soil structure, and human-induced deforestation also change vegetation patterns. |
| Compression of Mount Abu |
Mount Abu (cool mountain climate) was also placed in the 'Aw' class, which is thermally inconsistent. |
| Simplification of Vast Area |
About 60% of Rajasthan's desert region was compressed into only two categories (BWhw and BShw). |
📖 11.6 Key Exam Pointers
| Fact |
Description |
| Representative Districts |
BWhw → Bikaner, BShw → Nagaur, Cwg → Tonk, Aw → Dungarpur |
| Largest Zone |
Steppe) |
| Tropic of Cancer & Aw |
Banswara & Dungarpur (Tropic of Cancer) → Aw Zone |
| Meaning of 'g' |
Gangetic thermal pattern |
| Teak Forests |
Only in Aw Zone |
| Xerophyte Vegetation |
Only in BWhw Zone |
📖 11.7 Comparative Study
| Aspect |
BWhw |
BShw |
Cwg |
Aw |
| Rainfall |
10-20 cm |
20-40 cm |
60-80 cm |
80-150 cm |
| Representative District |
Bikaner |
Nagaur |
Tonk |
Dungarpur |
| Vegetation |
Xerophytes |
Steppe |
Deciduous |
Savanna/Teak |
| Temperature |
45-50°C |
38-42°C |
34-40°C |
30-35°C |
| Area |
Medium |
Largest |
Medium |
Medium |
Exam Revision#
Natural vegetation -> temperature and rainfall -> Koppen letter codes -> BWhw, BShw, Cwg, Aw -> representative districts -> exam comparison
rajasthan-koppen-climate-classification, koppen, koppen-letter-codes, bwhw, bshw, cwg, aw, natural-vegetation, desert-climate, steppe-climate, gangetic-climate, savanna-climate