我国历史时期冷暖年代的干旱型

中国历史时期的旱涝变化与冷暖变化是有联系的。冷的年代,我国的气候是西干东湿,而暖的年代则是西湿东干。

THE PATTERNS OF DRYNESS FROM COLD AND WARM DECADES IN HISTORICAL TIMES OF CHINA

This article is based on the historical climatic data of China.Sixteen decades with cold winter and sixteen decades with warm winter are selected from the period of 1471-1970,and the rest eighteen decades in this period are considered as normal.The change of dryness/wetness correlated with the change of cold/warm in this period.The patterns of dryness corresponding to the 3 kinds of decades introduced above are thus established.It is found that in the cold decades the climate is drier in the west than in th east and wetter in the east than in the west of China,but in the warm decades the pattern becomes converse.These results are supported by an evidence from an article on the ruins of ancient cities in the desert of the middle reaches of Huanghe River and some other evidences from the investigation of the historical low water along the upper reaches of the Changjiang River since 8th century from archaeological approach.It may be inferred that if the climate of the world is getting warmer than today,the areas westward from 110°and northward from -10°N will become wetter,but the area in the Plain of North China will become very dry.