Koeppen's Scheme of Climatic Classification

• Wladimir Koeppen provided his scheme of classification in 1900 which was modified later multiple times.

BASIS OF CLASSIFICATION

• He used french plant physiologist Candolle classification of major global vegetation types to classify major climatic types as he believed vegetation is holistic expression of climate of a place
• Koppen used annual temperature and precipitation data and seasonal variations to delineate different climatic zones.
• He used alphabets as symbols of these climates.Capital letters for major types and small letter for subtypes of climate.

Vegetation zones by Candolle	Major climate types(symbols)	Temperature and precipitation criteria
Megatherms	Tropical,A	Average temperature of all months is greater than 18 °C
Xerophytes	Dry,B	Evaporation exceeds precipitation
Mesotherms	Warm Temperates,C	Temperature of coldest month less than 18 °C but greater than -3;Temperature of warmest month greater  than 10 °C
Microtherms	Humid cold,D	Temperature of coldest month below -3 °C but warmest month above 10
Hekistotherms	polar,E	Temperature of warmest month less than 10 °C

• He further classified these major climatic zones into subtypes primarily based on precipitation pattern and has used small case letter for this second level of classification.

f	Precipitation throughout the year
m	Monsoon climate i.e short dry season
s	Summer dry
w	Winter dry

• On the basis of these, he categorised these 5 major types into further 11 subtypes.

SOME CLIMATE TYPES

1. Western european type (Cf)
2. China Type(Cw)
3. Mediterranean type(Cs)

EVALUATION

Merits

1. Relation between vegetation types and climate
2. Descriptive,generalized and simple.

Demrits

1. Overemphasis on average temperature and precipitation and neglecting other whether elements like no of rainy days,temperature extremes,wind,etc
2. No importance to air mass influence.
3. Lots of symbols makes it difficult to memorize.