| 摘要: |
| 利用华南110 个测站1961—2008 年逐日降水资料,通过EOF 分析、功率谱分析和计算趋势系数 等统计诊断方法,分析了华南年、前汛期、后汛期的雨日、雨强以及降水量的时空特征和气候变化。结果表明:华南年雨日以4.8 d/(10 a)的速率明显减少,但前、后汛期雨日减少趋势不明显。华南年雨日长期趋势变 化有明显的空间差异,在广西北部、华南沿海和海南,减少速率高达9～17.8 d/(10 a),其中海南的白沙减少趋势最为明显。华南年平均雨强以0.4 mm/(10 a·d)的速率明显增加,但平均雨强前汛期变化趋势不明显,后汛期明显。年雨强增加速率在海南、华南沿海和广西北部高达0.4～1.1 mm/(10 a·d),最大值出现在海南的五 指山和三亚。华南降水量和雨日的长期变化趋势不相似,但与雨强的变化趋势大部分相似。小波分析表明: 华南年雨日和降水量都有2～3 年、3～5年两个显著周期,年雨强在2000 年后有2～3 年的显著周期。根据 EOF 分析,华南雨日、雨强和降水量主要有“ 全区一致型” 、“ 东西差异型” 和“ 南北差异型” 三种分布型。 |
| 关键词: 气候变化 雨日 雨强 降水量 华南 EOF 趋势系数 |
| DOI：10.3969/j.issn.1004-4965.2011.06.011 |
| 分类号: |
| 基金项目:中国气象局气候变化专项(CCSF-09-11、CCSF-09-03);中国适应气候变化项目(ACCC);广州区域气象中心重点项目(GRMC2007202)共同资助 |
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| CLIMATIC VARIATIONS OF WET DAYS AND RAIN INTENSITY IN SOUTH CHINA |
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WU Hong-yu1, DU Yao-dong1, CHEN Zhen-hua2, PAN Wei-juan1, DUAN Hai-lai1
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1.Climate Center of Guangdong Province, Guangzhou 510080, China;2.Zhongshan Meteorological Bureau, Zhongshan 528401, China
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| Abstract: |
| Based on the daily precipitation data of 110 observational stations during 1961—2008 in South China, the climatic change and spatial temporal features of wet days, rain intensity and rainfall were studied for their annual and seasonal (e.g., the yearly first and second flood seasons) behavior in South China by using statistical diagnostic methods of empirical orthogonal function, power spectrum function and computing trend coefficients. Results show that the annual mean wet days have declined significantly at a mean rate of 4.8d/(10 a), but the variation trend of mean wet days is not obvious in the yearly first and second flood seasons in South China. As far as the long-term spatial variation trend is concerned, the reduction of annual wet days is the largest in north Guangxi, coastland of South China and Hainan, where the reduction rate is up to 9～17.8 d/10 a, especially in Baisha. The annual mean daily rain intensity increased greatly at a rate of 0.4 mm/(10 a·d) but less so in the yearly first and second flood seasons. The largest increase of annual rain intensity is seen in northern Guangxi, coastal South China and Hainan, where the increase rate is up to 0.4～1.1 mm/(10 a·d), with the largest in Wuzhishan and Sanya. The long-term trend variation of wet days is not similar to that of rainfall, but for the most part it is the same as that of rain intensity. The wavelet analysis shows that the changes in wet days and rainfall have significant 2～3 and 3～5 year periods. Rain intensity has significant 2～3 year periods beginning from 2000. There are three distribution types of wet days, rain intensity and rainfall based on the EOF analyses; the anomaly is either the same throughout the whole area or opposite in the south versus the north or in the east versus the west. |
| Key words: climatic variation wet day rain intensity precipitation South China empirical orthogonal function trend coefficient |
