THE CLIMATE OF CHINA ACCORDING TO THE NEW THORNTHWAITE CLASSIFICATION

N this paper climatic maps of China proper and Manchuria according to the Thornthwaite 1948 classification', are presented and discussed. The maps were prepared originally on a scale of 1 to 5 million under the direction of Dr. C. W. Thornthwaite at the Laboratory of Climatology, The Johns Hopkins University. Altogether, data of 285 climatic stations were used (Fig. 1). Thornthwaite recognized that the moisture condition of a place cannot be determined by measuring the precipitation alone; that it must be gauged by comparing the precipitation with the potential evapotranspiration. He also derived an empirical formula for computing the potential evapotranspiration as a function of temperature and latitude. Out of this idea and kindred ones Thornthwaite developed a climatic classification. The procedures of computing the potential evapotranspiration and the details of his classification will not be discussed here, since the reader may refer to his original paper. In presenting the climatic conditions Thornthwaite forsakes the attempt to depict them on one map. Instead he gives four maps: annual potential evapotranspiration, moisture index, seasonal variation of effective moisture, and summer concentration of thermal efficiency.