降水量とその年変化型による中国の地域区分

抄録

An attempt was made to study the subdivision of China by the annual amount and the annual variation type of precipitation using the mean values for the years 1951_??_1980 at the 1000 stations. Roughly speaking, the annual precipitation decreases from the lower lati-tudes to the higher latitudes and from the coasts to the inlands. The amplitudes of annual variation were normalized and, using these values, the principal component analysis was applied to determine the annual variation types. The results show that they are expressed by combinations of the two variation types in almost whole regions of China: (i) a type which has smaller amounts in the months of first half year and larger amounts in the months of second half year, in particular, in July, August and September, and (ii) another type which has larger amounts in the months of first half year, especially in April, May and June, and quite small amounts in the second half year. The former type of annual variation appears broadly in China and the latter type characterizes the South China region. There found no statistically significant type of annual variation in the northwestern desert region, because the monthly amounts are very scarce. In conclusion, China is sub-divided into 13 regions by the 11 types.