近40年来中国降水量、雨日变化趋势及与全球温度变化的关系

THE CHANGE TREND IN RAINFALL、WET DAYS OF CHINA IN RECENT40 YEARS AND THE CORRELATION BETWEEN THE CHANGE TREND AND THE CHANGE OF GLOBE TEMPERATURE

近40年来中国降水量的空间分布与相应时段的雨日数空间分布较一致;年降水量变化趋势主要呈现东北-西南向“+、-、+”分布型,其中以西部地区和长江三角洲的增加和华北及川东地区的减少趋势更加显著。对季降水来说,除了冬季降水量场表现为绝大部分地区为正趋势外,其它三季变化都较复杂;绝大部分地区年雨日数的趋势系数是负值,就是说雨日数总的趋势是减少的,全国范围内秋季雨日数明显呈现减少的趋势;夏季强降水日的平均频数介于0～11之间,最大值位于西南地区的西部,最小值则位于南疆地区;无论是降水量场还是雨日数场都与全球温度距平存在显著相关,只是后者的显著性水平高于前者。

The spatial distribution of the annual and seasonal precipitation is consistent with the spatial distribution of the wet days in corresponding phases; the changing trend of annual rainfall appears in the distribution pattern of ＂＋. -. ＋＂ from northeast to southwest, and it is more notable that there is positive trend in West China and the delta of Changjiang River and negative trend in North China and western Sichuan province; The changing trend of seasonal precipitation field in spring, summer and autumn is very difficult to describe ,except that most areas have positive trends of winter precipitation field; The negative trend of annual wet days appears in most areas of China, notable negative trends of wet days occur in autumn; it is on average from 0 to 11 days with the intensity of heavy precipitation, the maximum value situates on the western part of Southwest China,the minimum value situates in southern XinJinag; there is notable correlation between the annual rainfall field and the anomaly of global temperature, meanwhile the correlation is also notable between the annual wet day field and the anomaly of global temperature, but the reliability of the latter is more than that of the former.