Abstract:

Based on the daily observation data of 16 stations of Guizhou Province from the National Meteorological Information Center, the reanalysis data from NCEP/NCAR and the global SST (Sea Surface Temperature) data from NOAA, the spatial and temporal distribution of drought and flood based on SPI in Guizhou Province was analyzed by using EOF and Morlet wavelet analysis methods, firstly. And the atmospheric circulation in abnormal drought/flood years in Guizhou Province and relationship between SPI and global SST were also researched. The results are as follows: (1) The consistent anomaly distribution was the main spatial model of drought/flood variation feature in Guizhou Province in each season, and in spring and summer it presented drought trend in some extent. The drought/flood in spring and autumn had a two-year and ten-year periodic fluctuation, while in summer and winter there was two-year, three-year and five-year periodic fluctuation. (2) If the Western Pacific subtropical high (WPSH) became stronger (weaker) and westward (eastward), there was less (more) rainfall, and drought (flood) would happen in spring and autumn. If the WPSH was southward (northward) and its position was eastward (westward), then there was less (more) rainfall, and drought (flood) would appear in winter and summer. (3)The autumn SPI had a significant negative correlation with global SST during the previous period and the corresponding period. The key area was the eastern Indian ocean and the western Pacific.

Key words: Guizhou Province, distribution of drought and flood, the Western Pacific subtropical high;sea surface temperature, correlation

摘要：

利用国家气象信息中心整编的全国753站中贵州省16站逐日观测资料、NCEP/NCAR再分析资料以及NOAA的月平均海表温度资料，采用经验正交函数（EOF）展开、Morlet小波分析等方法对基于标准化降水指数（SPI）的贵州省旱涝时空分布特征进行研究，并分析贵州旱涝异常时的环流特征及与全球海表温度的关系。结果表明：（1）贵州SPI的各季节主模态空间分布均为全区一致型，春秋两季还表现出一定的干旱化趋势；春季和秋季的旱涝分布存在2 a、10 a左右的振荡周期，而夏季和冬季的振荡周期则以2 a、3 a及5 a左右为主；（2）春秋两季，当西太平洋副热带高压主体强度偏强（弱）、位置偏西（东）时，贵州地区降水偏少（多），易发生干旱（洪涝）；而冬夏两季，当西太平洋副热带高压主体偏北（南）、位置偏东（西）时，贵州地区降水偏少（多），易发生干旱（洪涝）；（3）贵州秋季SPI与前期、同期东印度洋—西太平洋区域的海温存在显著的负相关。

关键词: 贵州省, 旱涝分布, 西太平洋副高, 海表温度, 相关性