渭河流域降水和气温的时空特征分析

Temporal and Spatial Characteristics of Temperature and Precipitation in Weihe River Basin

降水和气温等气候要素对农业生产具有显著影响。根据1957—2009年渭河流域内12个代表性气象站点53a的降水和气温实测资料,采用传统统计、经验正交函数分解(EOF分析)和小波分析等方法,讨论了渭河流域降水量和气温的空间分布特征,并分析了其周期变化特点。结果表明:(1)受大尺度天气系统影响,流域降水量和气温异常的一致性是主要特点,也存在南北差异和东西差异;(2)年降水量主要存在30a或更大的周期变化特征,而年平均气温、年平均最低气温和年平均最高气温主要存在29a或更大的周期变化特征。

Climate factors including precipitation and temperature have significant effects on agricultural pro- duction. Traditional statistics, EOF analysis and wavelet analysis were applied to analyze the characteristics of periodic variations and spatial distribution of precipitation and temperature in this region based on data col- lected at the 12 weather stations in Weihe River basin during 1957--2009. The results show that： （1） The precipitation and temperature in the basin is affected by larger scale weather systems. The abnormity of pre- cipitation and temperature in Weihe River basin were simultaneous, and the abnormity of precipitation and temperature differed between south and north, and in the east and west. （2） Morlet wavelet transform indi- cated that the major periods for precipitation was about 30 years or more, while the main periods for annual mean temperature and mean maximum temperature were about 29 years or more.