11.1. KOEPPEN'S SCHEME OF CLASSIFICATION OF CLIMATE

The most widely used classification of climate is the empirical climate classification scheme developed by V. Koeppen. Koeppen identified a close relationship between the distribution of vegetation and climate. He selected certain values of temperature and precipitation and related them to the distribution of vegetation and used these values for classifying the climates. It is an empirical classification based on mean annual and mean monthly temperature and precipitation data. He introduced the use of capital and small letters to designate climatic groups and types. Although developed in 1918 and modified over a period of time, Koeppen’s scheme is still popular and in use.

Koeppen’s classification is one of the most important systems that help in understanding climate. He realized that different types of plants grow in different climates and that temperature and rainfall patterns influence this distribution. By examining average temperatures and rainfall data, he was able to create a systematic way to categorize climates into groups using both capital and small letters. This system, introduced in 1918, has seen modifications over the years but remains widely used due to its effectiveness.

Think of Koeppen's classification like a restaurant menu. Just as a menu categorizes food types—like appetizers, main courses, and desserts—Koeppen sections climates into groups based on temperature and precipitation so that we can easily understand and study different climates around the world.

Koeppen recognised five major climatic groups, four of them are based on temperature and one on precipitation. The capital letters: A, C, D, and E delineate humid climates and B dry climates. The climatic groups are subdivided into types, designated by small letters, based on seasonality of precipitation and temperature characteristics.

Koeppen identified five main groups of climate: A (Tropical), B (Dry), C (Warm temperate), D (Cold), and E (Cold tundra). The 'A', 'C', 'D', and 'E' groups indicate humid climates with varying temperatures, while 'B' indicates dry climates. Each group is further divided using lowercase letters which describe specific seasonal patterns of precipitation and temperature changes, allowing for a more precise understanding of each climate type.

Imagine you have five friends, each representing a climate group. Each friend has a unique personality (climate) based on where they live (temperature and rainfall). Just as you might divide your friends into categories based on their interests, Koeppen divides climates into groups based on their characteristics.

The capital letters A - Tropical, B - Dry Climates, C - Warm Temperate (Mid-latitude) climates, D - Cold Snow Forest Climates, E - Cold Climates. The climatic types are listed in Table 11.2. The small letters a, b, c and d refer to the degree of severity of temperature.

Each of Koeppen's main climatic groups is characterized by specific temperature and precipitation patterns. For example, 'A' is for tropical climates that are consistently warm and wet, while 'B' is for arid climates where evaporation exceeds precipitation. The small letters denote variations within each group, showing subtleties like whether a climate has a dry season or how extreme temperature ranges can be.

Consider Koeppen's groups like categories of clothing. Just as winter clothes (cold climates) are much different from summer clothes (tropical climates), these climatic groups show how weather patterns dictate the natural environment we encounter, from the lush tropical jungles to the barren deserts.