黄山地区汛期(5-9月)降水时空特征

用谱分析、连续小波变换和经验正交(EOF)分解分析了黄山地区近45年来汛期(5—9月)降水序列时空分布特征。结果表明:黄山地区整体上都有3～4年和16～20年旱涝显著周期,另外其西北部还有10年左右旱涝周期,目前黄山地区正处于45年来第三个干旱期中。从EOF分解的空间第一模态看出,黄山地区降水空间分布与黄山山脉走向紧密相连,并可分为中西部型、南部型、东北部型三个主要类型。

Spatial-Temporal Characteristics of Precipitation in Flood Season in Huangshan Mountains

The spatial-temporal distribution characteristics of precipitation in the flood season(from May to September)of past 45 years in Huangshan are analyzed with spectral analysis,continuous wavelet transformation and empirical orthogonal function(EOF)decomposition techniques.The results indicated that there are obvious drought/flood cycle about 3-to 4-year and 16-to 20-year in Huangshan as a whole,while there is drought/flood cycle about 10-year in its northwestern region.At present,Huangshan is in the third drought period during the past 45 years.By the first space mode decomposed with EOF,it is found that the spatial distribution of precipitation has close relationship with the orientation of Huangshan mountain.The spatial anomaly of precipitation can be divided into three patterns,i.e.,the mid-west type,south type and northeast type.