【摘要】 本文基于中国551站1961~2000年的逐日降水资料,对不同季节和全年降水量的变化趋势进行了分析。结果表明,北方地区除东北外近 40a来气候呈现干旱化趋势,尤其是河套地区标志线明显东移,半干旱区逐年东移;年的干旱化主要发生在河套地区,各季的干旱化分布不尽相同,有强有弱,有早有迟,但多是以河套地区为主,四季均表现为干旱化。更多还原

【Abstract】 Based on the daily precipitation data of 551 stations in China from 1961 to 2000, the varying tendencies of precipitation have been analyzed in the seasonal and annual variation. It shows aridification in the northern area during the last 40 years, especially in the Hetao Area. The symbolical boundary moves to east and the semi-arid region enlarges annually. The annual aridification mainly takes place in the Hetao Area. It is different in each season. But the most variations take place in the Hetao Area, in which it shows aridification in four seasons.更多还原