近41年中国不同季节降水气候分区及趋势

利用中国486个测站1960—2000年逐日降水观测资料,采用分层聚类和相似分析方法,兼顾降水的年内季节变化和年际变化,对中国降水进行了气候区划。利用动态分析分层聚类过程中组内和组间平均相关系数的差异指标法,为不同季节降水研究找到了适合的分区方案。在年降水分区方案中,得到中国降水的三级气候分区:11区、28区和54区。用同样的方法得到各月、季降水的分区方案。在分析过程中发现:在同样相似条件下,夏季(及夏季各月)分区数明显多于其它季(月);11个Ⅰ级分区年降水具有明显的区域性特征。分析结果在一定程度上说明了所用分区方法的客观性。

The Seasonal Climate Division and Precipitation Trends of China in Recent 41 Years

Using the day-to-day precipitationdata at 486 stations of China during 1960-2000 and the differential cluster analysis and analogues analysis,as well as taking account of the seasonal and interannual changes of precipitation,the climate regions are divided according to precipitation in China.The suitable sub-region schemes are seeked for the study of different seasonal precipitation in China using the difference index method of interclass and intraclass average correlation coefficients in the dynamic analysis cluster process.The three sub-regions of precipitation in China are obtained in sub-region schemes of annual precipitation: 11,28 and 54 regions.With the same method,the sub-regions of monthly and seasonal precipitation are obtained too. The following climate characteristics can be drawn out from the above:(1) The number of sub-regionsof summer(and its months) is bigger than that of winter,obviously.The seasonal variation of precipitation can be divided into 20 sub-regions and annual variation can be divided into 40 sub-regions.The numbers of sub-regions in winter summer and half-year are both 25 and the numbers in spring,summer,autumn and winter are 25,30,30,22,respectively,in the twelve months,22,27,30,28,28,38,38,34,33,33,23,23.(2) The11 sub-regions of I level have local characteristics in the annual variation of ratio of precipitation in four seasons.