Explanation
The important features of Koppen; climatic classification is based on vegetation. It attempts to explain the variation of earth's climate by studying the connection between vegetation and climate. Koppean's classification of climates consists of five major climatic groups which are
A- This is moist and hot climate e.g tropical rainy climates with avenge mz.nthly temperature of above 18°C. This climate has no winter seasons. Annual rainfall is large and exceeds annual evaporation.
B - This is dry climate in which potential evaporation exceeds precipitation. Since there is no water surplus, no permanent streams originate in B climatic zones.
C - This refers to moist and warm climate e.g warm temperate climate, whose coldest month has an average temperatures of under 18°C but has above 3°C in at least one month. It has both summer and winter seasons.
D - This is snowy and cold climate (cold - snow forest climate). The average temperature of its coldest month is under 3°C. The average temperature of the warmest month is above 10°C
E -This is polar icy climate (snow climate). The average temperature of its warmest month is below 10°C. This climate has no true summer. In order to differentiate between sub-divisions within these major groups, secondary letters are assigned to furnish more complete explanation e.g
F - moist all year
M -monsoon conditions
S - dry summer wet winter
V - dry winter, wet summer.
A third letter was added to include information about temperature e.g
a - long hot su. rimer
b - short, warm summer
c - short and moderate or cool summer
d - very cold am; dry winter
h - hot and dry most of the year
k - cold and dry most of the year.
This is how these letters are assigned to climatic belts e.g polar and sub-polar (sub arctic) regions begin with the letter E, to which are added either T (for tundra vegetation and conditions). The dry climates are assigned the letter W and S to differentiate between desert (BW) and steppe (BS) climate and vegetation conditions. BWK would refer to cool desert climate while DFe would refer to cold snowy forest climate with cool short summer.
