CLIMATIC DIAGRAMS AS A MEANS TO 

 COMPREHEND THE VARIOUS CLIMATIC TYPES 

 FOR ECOLOGICAL AND AGRICULTURAL 



PURPOSES 



H. Walter 



Botanisches Institut, Stuttgart-Hohenheim, W. Germany 



A very close correlation exists between vegetation and climate. Therefore 

 everyone who is interested in vegetation should be equally interested in 

 cHmate. 



It is very difficult, however, to get an exact idea of chmate. We con- 

 stantly use the word 'chmate', but what is cHniate? It is possible to defme 

 chmate as the weather, changing in a certain mamier during the course of 

 a year, taken as an average of many years, as a single year may be abnormal. 



What is the weather ? It is the effect of all weather or climatic elements as 

 temperature, rainfall, humidity, radiation, etc., combined at a certain 

 moment. Therefore, to get the actual chmate, it is necessary to summarise 

 the effects of all these chmatic elements in order to get the weather for 

 the entire year. But no chmatologist tells us how to do this. It is only 

 possible to get the tables for each climatic element. We also have many 

 exact maps of the distribution of the annual temperature or the annual 

 rainfall, the temperature of the coldest or hottest month, the rainy seasons, 

 the humidity, the evapotranspiration, etc., but all this does not yet fuUy 

 constitute the climate. As basis for chmatic maps the chmatologist employs 

 chiefly the maps of vegetation and also the climatic types are named after 

 the vegetation, for example, desert chmate, steppe chmate, forest chmate, 

 alpine chmate, etc. 



Climate is a unity. It is not possible to express cHmate by a figure or by 

 formulae, even by the most compHcated ones, because it is necessary to 

 know the seasonal rhythm of the most important factors. Therefore we 

 have to use a diagram, quasi as a picture of the chmatic type. 



During the year 1954-55 I was a guest professor at Ankara in Anatolia 

 and I desired a quick overall picture of the different chmatic types of 

 Anatoha. I obtained the meteorological tables from approximately 66 

 meteorological stations with long-term observations, but it was very 

 difficult to get a synopsis of the chmatic regions. I decided to use the 

 diagram method and I remembered a suggestion given by H. Gaussen at 

 the International Botanical Congress in Paris in 1954 to use the same units 



