UPSC MainsGEOGRAPHY-PAPER-II201230 Marks
Q2.

Discuss the role of spatial pattern of rainfall and temperature in the delimitation of climatic regions of India, specially with reference to stamp's climatic regionalization.

How to Approach

This question requires a detailed understanding of Indian climatology and how spatial variations in rainfall and temperature influence the delineation of climatic regions. The answer should focus on Stamp’s climatic regionalization of India, explaining his methodology and the rationale behind his classification. It’s crucial to link the climatic regions to specific temperature and rainfall patterns. A structured approach involving an introduction, detailed explanation of Stamp’s classification with examples, and a conclusion is recommended. Include relevant data and geographical examples to strengthen the answer.

Model Answer

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Introduction

India, due to its vast geographical expanse and diverse topographical features, exhibits significant variations in temperature and rainfall. These variations are fundamental in determining the country’s climatic regions. Climatic regionalization is the process of dividing a country into areas with similar climatic characteristics. While several attempts have been made to classify India’s climate, the work of Dudley Stamp stands out for its comprehensive and widely accepted methodology. Stamp’s classification, published in 1959, utilized rainfall and temperature data to delineate distinct climatic regions, providing a foundational framework for understanding India’s climatic diversity. This answer will discuss the role of spatial patterns of rainfall and temperature in delimiting these climatic regions, with a specific focus on Stamp’s regionalization.

Understanding the Role of Rainfall and Temperature

Rainfall and temperature are the two most crucial elements influencing climate. Their spatial distribution across India is highly uneven. The Himalayas act as a barrier to cold winds, influencing temperature patterns. The monsoon winds, responsible for most of India’s rainfall, are also spatially variable due to factors like orography and distance from the sea. This interplay of factors creates distinct climatic zones.

Stamp’s Climatic Regionalization of India

Dudley Stamp, in his ‘The Climates of India’, categorized India into eight major climatic regions based on rainfall, temperature, and their seasonal distribution. His classification is largely based on the concept of ‘climatic provinces’ – areas with relatively homogeneous climatic conditions.

1. Hot and Dry Climate

This region covers parts of Rajasthan, Gujarat, and Haryana. Characterized by high temperatures (mean annual temperature above 28°C) and very low rainfall (less than 750mm), it experiences scorching summers and mild winters. The rainfall is erratic and unreliable. The Thar Desert falls within this zone.

2. Hot Semi-Arid Climate

Found in the leeward side of the Western Ghats and parts of Punjab, Haryana, and Rajasthan. Rainfall ranges between 750mm and 1000mm, and temperatures are high, though slightly lower than the hot and dry climate. This region is prone to droughts.

3. Warm and Humid Climate

This region encompasses the coastal plains of India, including the eastern and western coasts. High temperatures and high humidity are characteristic, with rainfall exceeding 2000mm annually. The monsoon plays a dominant role, and the region experiences prolonged wet seasons.

4. Monsoon Climate

This is the most widespread climatic region, covering most of the Indo-Gangetic Plain and parts of central India. It experiences distinct wet and dry seasons, with rainfall between 1000mm and 2000mm and moderate temperatures. The monsoon winds are the primary source of rainfall.

5. Tropical Savannah Climate

Found in parts of the Deccan Plateau and the eastern Ghats. Characterized by moderate temperatures and moderate rainfall (750mm-1500mm) with a distinct dry season. Vegetation consists of grasslands and scattered trees.

6. Cool and Dry Climate

This region includes parts of Jammu and Kashmir, Himachal Pradesh, and Uttarakhand. Low temperatures and low rainfall are characteristic, with snowfall during winters. The region experiences a continental climate.

7. Cool and Wet Climate

Found in the higher reaches of the Himalayas, particularly in Jammu and Kashmir and Himachal Pradesh. Low temperatures and high rainfall (exceeding 2000mm) are characteristic, with heavy snowfall during winters. This region supports temperate forests.

8. Alpine Climate

This region is found in the highest altitudes of the Himalayas. Characterized by extremely low temperatures, heavy snowfall, and a short growing season. Vegetation is sparse and limited to alpine meadows.

Spatial Patterns and Regional Delimitation – Examples

The spatial pattern of rainfall is crucial. For instance, the Western Ghats receive orographic rainfall, leading to the warm and humid climate along the coast. Conversely, the leeward side experiences a rain shadow effect, resulting in the hot semi-arid climate. Similarly, temperature variations, influenced by latitude and altitude, contribute to the differentiation between the cool and wet climate in the Himalayas and the hot and dry climate in Rajasthan. The monsoon trough’s position also significantly impacts rainfall distribution and, consequently, the climatic regions.

Climatic Region Rainfall (mm) Temperature (°C) - Mean Annual Key Characteristics
Hot and Dry < 750 > 28 Scorching summers, low rainfall, desert conditions
Warm and Humid > 2000 25-30 High humidity, prolonged wet season, coastal areas
Alpine Variable, mostly snow < 0 Extremely low temperatures, heavy snowfall, high altitudes

Conclusion

Stamp’s climatic regionalization of India, based on the spatial patterns of rainfall and temperature, remains a valuable framework for understanding the country’s climatic diversity. While modern classifications incorporate additional factors like humidity and vegetation, Stamp’s work provides a foundational understanding of the interplay between these climatic elements and their influence on regional characteristics. Recognizing these spatial variations is crucial for effective planning in sectors like agriculture, water resource management, and disaster mitigation, especially in the context of a changing climate.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Orographic Rainfall
Rainfall that occurs when moist air is forced to rise over mountains, cools, and condenses.
Monsoon Trough
An elongated low-pressure area extending from the Arabian Sea to the Bay of Bengal, which is responsible for the majority of rainfall during the monsoon season in India.

Key Statistics

Approximately 65% of India’s total geographical area is prone to drought.

Source: National Disaster Management Authority (NDMA), 2023 (Knowledge Cutoff)

India receives approximately 75% of its annual rainfall from the Southwest Monsoon (June-September).

Source: India Meteorological Department (IMD), 2022 (Knowledge Cutoff)

Examples

Cherrapunji and Mawsynram

These locations in Meghalaya receive the highest average rainfall in the world due to their location on the windward side of the Khasi Hills, exemplifying orographic rainfall and the warm and humid climate.

Frequently Asked Questions

How does climate change affect Stamp’s classification?

Climate change is altering rainfall patterns and increasing temperatures, potentially leading to shifts in the boundaries of Stamp’s climatic regions. For example, increased frequency of extreme weather events like droughts and floods may blur the lines between different climatic zones.

Topics Covered

GeographyClimatologyIndian ClimateRegional ClimateClimate Classification