中国半个世纪以来夏季降水量变化总趋势

Precipitation trend analysis in China in the last half century

全球气候变化已经影响到人类生存环境的方方面面。全球升温及其幅度的区域差异,必然引起降水在区域分布的变化。文章利用160站点的夏季降水资料,分别计算出各个站点1951—2002年的变化斜率,以展示我国各地在这半个世纪中的降水总趋势变化的区域差异。通过分析发现,降水量总的变化趋势存在着随纬度而变化的规律:31°N以北区域近半个世纪降水量总的变化趋势是减少,31°N以南地区降水量以增加为主。40°N以北地区的降水变化幅度相对要小得多。区域上,中国西北和东南存在一个降水增多的趋势。中国降水的区域变化,在季风区受季风强弱变化影响;在非季风区,受西风强弱变化影响。

The unprecedented global warming is causing many environmental problems. Due to the differences of warming extents in various regions, precipitation is bound to be affected by the asynchronous warming. The trend of summer precipitation variation series of 160 stations are analyzed to find general trend of precipitation change under global warming in 1951-2002. Results showed that there is a significant regional precipitation variation difference. By analysis, we found out that the precipitation has a latitudinal effect, that the precipitation generally kept a decline trend in the area north to 31°N, but a increase trend to the south of 31°N. the precipitation in the area north of 40°N is more stable in variation than in the lower areas. Regionally, the precipitation in Northwest China and Southeast China kept obvious increasing trends. The precipitation variation in the summer monsoon influenced areas is controlled by the variety of the summer monsoon and that in the non-summer-monsoon influenced area results from the variation of the westerly.