“水”是农业的命脉。影响我国农业布局、产量提高的往往并不一定是生长季的热量不足,而是受了水分条件的限制。目前我国耕地面积中,约有1/3地区,经常受着水旱灾害的威胁。本文从气候学角度结合农业,对全国干湿情况进行分型和区划。此外,本文还讨论了我国干湿类型及时空分布的特征,以期为进一步探讨各地区水旱发生发展规律及其形成原因提供论据。

In this paper, the dry and wet climatic regionalization of China is made on the basis of the data of 286 stations for the years from 1951 to 1960. Aridity is taken as the first index for the regionalization, which shows the annual state of dryness and wetness. Aridity is the ratio of the potential evaporation and the precipitation, in which the poten- tial evaporation is obtained from the H. L. Penman's formula. Then types of dryness and wetness are used as the second index which shows the seasonal changes. On this basis, China is divided into four climatic zones, i.e. wet, semi-wet, semi-dry and dry, which are called "Class I" regionalization. There is good agreement between the natural landscape and the aridity in general. Then we made use of the dry and wet frequency in the analysis of the dry and wet distribution in various seasons. On this basis, 15 dry and wet types are derived, five of which being fundamental dry and wet types. The dry and wet distributions in each season are closely related with the feature of the general circulation. According to Class I and the dry and wet types, China is divided into 25 dry and wet regions, which are called "Class II" regionalization.