Climate Classification of India: K ppen and Trewartha Systems Explained

Introduction to Climate Classification

Climate classification systems categorize different regions based on their climatic characteristics. For India, these classifications are vital due to the country's vast geographical diversity. India experiences a wide range of climates, from tropical in the south to alpine in the Himalayas. These systems help in systematic study and comparison of climatic patterns across various parts of the country. They also provide a framework for understanding the distribution of vegetation, soil types, and agricultural practices.

The two most widely recognized systems for classifying India's climate are the K ppen system and the Trewartha system. Both systems use different parameters to define climate zones, but they aim to provide a clear picture of the climatic variations. These classifications are not just academic; they have practical applications in urban planning, disaster management, and resource allocation. Aspirants should focus on the key parameters and the resulting climate types for different Indian regions.

Köppen Climate Classification

The K ppen climate classification system is one of the most widely used systems globally. It was developed by Wladimir K ppen in 1884, with several revisions later. This system primarily uses annual and monthly averages of temperature and precipitation to define climate zones. It also considers the seasonality of precipitation. The main climate groups are denoted by capital letters: A (Tropical), B (Dry), C (Temperate), D (Continental), and E (Polar).

For India, the K ppen system identifies several distinct climate types. These include 'Amw' (Monsoon type with short dry winter) found along the west coast, 'As' (Monsoon type with dry summer) in parts of Tamil Nadu, 'Aw' (Tropical savanna type) covering most of Peninsular India, and 'BShw' (Semi-arid steppe type) in parts of Rajasthan and Gujarat. 'BWhw' (Hot desert type) is found in the Thar Desert. 'Cwg' (Monsoon type with dry winter and cool summer) is seen in the Ganga plains, while 'Dfc' (Cold humid winter with short summer) and 'ET' (Tundra type) are found in the Himalayan regions. Understanding these specific codes and their corresponding regions is essential for exams.

Trewartha Climate Classification

The Trewartha climate classification system is a modified version of the K ppen system, developed by Glenn Thomas Trewartha in 1966. It simplifies some of K ppen's categories and is often considered more practical for regional studies. Trewartha's system uses fewer main climate types, focusing on temperature and precipitation characteristics. The primary groups are A (Tropical), B (Dry), C (Subtropical), D (Temperate), E (Boreal), and F (Polar).

In India, the Trewartha system also provides a clear picture of climatic zones. It identifies 'Am' (Tropical Monsoon) along the western coast and northeastern India, 'Aw' (Tropical Wet-Dry) over a large part of Peninsular India, and 'BS' (Semi-arid) in regions like Rajasthan and Gujarat. 'BW' (Desert) is found in the Thar Desert. 'Cfa' (Humid Subtropical) covers the northern plains, while 'H' (Highland) is used for the Himalayan regions. The Trewartha system often provides a broader classification, making it easier to grasp the general climatic patterns of large areas. Both systems are important, and aspirants should be able to differentiate between their approaches and classifications.

Factors Influencing India's Climate

Several geographical and atmospheric factors influence India's diverse climate, leading to the classifications discussed. The most significant factor is the presence of the Himalayas in the north. These mountains act as a barrier, preventing cold winds from Central Asia from entering India and trapping the monsoon winds, leading to heavy rainfall on their southern slopes. The Peninsular shape of India, surrounded by the Arabian Sea, the Bay of Bengal, and the Indian Ocean, also plays a crucial role, influencing monsoon patterns and coastal climates.

The monsoon winds are another dominant factor. The South-West Monsoon brings most of the rainfall to India between June and September, while the North-East Monsoon affects parts of South India during winter. Altitude also significantly impacts temperature and precipitation, with higher altitudes experiencing colder temperatures and often more snowfall. Latitude influences the amount of solar radiation received, with southern India being closer to the equator experiencing higher temperatures. Ocean currents, relief features, and jet streams also contribute to the complex climatic mosaic of India.

Important Keywords Explained

K ppen Climate Classificationconcept

A widely used system developed by Wladimir K ppen, classifying climates based on annual and monthly temperature and precipitation averages. It uses a series of letters to denote major climate groups and their sub-types, such as 'Amw' for tropical monsoon with a short dry winter.

Trewartha Climate Classificationconcept

A modified version of the K ppen system by Glenn Thomas Trewartha, often considered simpler and more practical for regional studies. It also uses temperature and precipitation data but with fewer main climate types, like 'Am' for tropical monsoon.

Monsoonconcept

A seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest in summer and bringing heavy rains (South-West Monsoon), and from the northeast in winter (North-East Monsoon), affecting parts of India.

Additional Facts & Context

• India has 6 major climatic types according to the K ppen system.
• The Thar Desert receives less than 150 mm of annual rainfall.
• The average annual rainfall in India is about 125 cm.
• Cherrapunji and Mawsynram in Meghalaya receive over 11,000 mm of rainfall annually.
• The highest temperature recorded in India was 51 C in Phalodi, Rajasthan, on May 19, 2016.