中国不同月份和持续时间降雨的变化趋势与波动特征的空间格局对比研究(1961—2015)

Comparison of Spatial Patterns of Trend and Fluctuation of Rainfall in Different Months with Different Durations in China from 1961 to 2015

采用1961—2015年中国535个站点日值降水数据,利用线性变化趋势和变异系数的方法,分析了中国不同月份和不同持续时间降水的空间变化格局.结果表明:(1)在变化趋势上,1961—2015年中国年际雨量变化趋势从东南沿海到西北内陆依次呈"增—减—增"的空间分异格局,而年际雨日变化趋势则呈"北部增加—南部减少"的空间分异格局.冬半年雨日呈增加趋势的地区明显多于夏半年,且增加幅度也较大,夏半年东部地区降水格局随月份变化明显,且增减趋势变化幅度相差较大.(2)在波动特征上,1961—2015年中国年际雨量和雨日的波动特征呈"北方高—南方低"的空间分异格局,且西北波动整体高于东北地区.(3)在不同持续时间上,持续2、3和4天以上的雨量和雨日变化趋势从东南沿海到西北内陆依次呈现出"增—减—增"的空间分异格局,而持续5、6和7天以上的雨量和雨日变化趋势以黑龙江黑河至云南腾冲一线为界呈现为"东南减少—西北增加"趋势.降雨持续天数越长,波动越大,且北方波动整体大于南方地区.研究发现中国降水随时间表现出的空间差异性在加剧.

In this research,535 stations’ meteorological datum during 1961—2015 from Daily Surface Meteorological Observation Data Sets were provided by National Meteorological Information Center of China Meteorological Administration. The spatial variation patterns of rainfall in different months and different duration in China were analyzed by using linear variation trend and variation coefficient. The results showed that： firstly,the trend of annual rainfall amounts during 1961—2015 showed ＂ increasing-decreasing-increasing＂ pattern from southeast coast to northwest inland in China. The annual trend of rainfall days presented the spatial pattern of ＂ north increasingsouth decreasing＂. Winter half year’s rainfall days increased significantly more than that in summer half year,and the increasing range was larger. The eastern region rainfall amounts and days with obvious seasonal change from May to October,and the amplitude of variation trend had large difference. Secondly,fluctuation during 1961—2015of annual rainfall amounts and days showed ＂ north high-south low＂ pattern,and fluctuation in northwest region was higher than that in northeast region. Thirdly,in different duration time,the trend of 2,3 and 4 days of rainfall amounts and rainfall days were showing a ＂ increasing-decreasing-increasing＂ pattern from the southeast coast to the northwest inland. Taking Heihe in Heilongjiang to Tengchong in Yunnan as the boundary line,we can see that the trend of 5,6 and 7 days of rainfall amounts and rainfall days,which showed ＂ southeast decreasing-northwest increasing＂ pattern. The longer rainfall lost,the greater rainfall fluctuated. And the northern region had the greater fluctuation than the southern region. This research incadicated that spatial difference of rainfall in China exacerbated