• 论文 •

### 近三十年我国夏季风盛行期降水的分析

1. 中国科学院地理研究所
• 出版日期:1981-04-15 发布日期:1981-04-15

### INTERANNUAL VARIATIONS OF RAIN SPELL DURINGPREDOMINANT SUMMER MONSOON OVER CHINAFOR RECENT THIRTY YEARS

Guo Qiyun, Wang Jiqin

1. Institute of Geography, Academia Sinica
• Online:1981-04-15 Published:1981-04-15

Abstract: Firstly, by using the normal decade rainfall data for eastern China to analyze theseasonal change of rainfall. Investigation shows that the maximum rainfall zone usuallystagnated for some days in South China when it moved from south to north, and did soin Changjiang Basin and North China respectively. These three periods of stagnationcoincided roughly with the time interval of predominant monsoon in above mentionedregions. But in Changjiang Basin the length of stagnating period was much shorterthan other two regions and even so a slight movement of maximum rainfall zone observedagain.Secondly, the rain spells for South China, Changjiang Basin and North China weredecided by using the pentad rainfall data year by year from 1951 to 1979. The begin-ning and ending dates, intermissions and persistences of rain spells were obtained. Therainfall sum for each raiii spell was calculated too. It is found that the charcteristics ofrain spells varied from one year to another obviously. The beginning dates of rain spellsexperienced the biggest interannual variations, especially in South China. The varia-tions of rain spells of one region rarely correlate with another.Thirdly, an analysis of long period rain spell variations shows that the trend wasmore predominant in Changjiang Basin. In general, the beginning of rain spell wasearlier, the duration was longer and the rainfall sum was much bigger in 1950s inChangjiang Basin and South China. On the contrary, the beginning of rain spell waslater and the length of rain spell was shorter, the rainfall sum was smaller in Chang-jiang Basin in 1960s. At the same time, the beginning of rain spell was earlier and thepersistence of rain spell was longer, but the rainfall sum did not increased much inNorth China. In 1970s, in both South China and North China the rain spells startedlater and ended later also. In the last decade the rainfall sum at Changjiang Basin hasa moderate value between the 1950s and1960s.