半个世纪以来黄土高原降水的时空变化

Spatial and temporal precipitation variation on the Loess Plateau in the past half century

在全球性的显著升温引起全球环境的一系列变化,而全球变暖必然被引起区域降水分布的改变。气候变化将改变全球水循环的现状,导致水资源时空分布的重新分配,并对降水、蒸散发、径流等造成直接影响。运用中国气象中心黄土高原51个站点的降水资料,通过Mann-Kendall趋势分析法,对1947-2004年期间的降水时空分布规律及其原因进行了分析。结果发现,多数站点的降水在半个世纪中呈现减少趋势,降水减少的突变时间大约在1983年;降水显著减少的区域为夏季风边缘地区,季风边缘地区的降水序列与东南季风指数之间存在很好的相关性,说明夏季风的变化是引起该区域降水变化的主要原因。

Global climate change makes great effects on the hydrology and water cycle. Accordingly, the study of climate change effect to region water resource has got prevalent attention in the world. Global warming is bringing about changes in precipitation patterns, with some areas increasing while other areas drying out. The monsoon climate, complicated landforms and airflows in China complicated the precipitation patterns and variations in China. In this paper, long-term precipitation data of 51 stations were applied to analyze the precipitation variation on the Loess Plateau in China, It was found that the precipitation of most stations kept a decrease trend in the duration of 1947--2004, the abrupt precipitation decrease mutations averaged in 1983; the areas with signifi- cant precipitation decrease lies at the twig of the summer monsoon covered area, and there is a good correlation between summer precipitation and the South-East Monsoon index, indicating that the precipitation variation mainly resulted from the variation of the South-East Monsoon.