广东省夏半年降水敏感区域分析

利用广东省25个台站1980年至2012年4-9月份的降水量资料,采用小波分析、EOF和REOF方法对夏半年降水量的周期振荡、空间异常特征以及时间变化规律进行诊断分析研究。结果表明：广东省夏半年降水总量存在显著的4a、7a和13a周期振荡,且4a周期振荡信号最强,为第一主周期,7a和13a分别为第二、第三主周期。其主要异常模态表现为一致偏少或一致偏多、沿海与内陆反向型。广东省夏半年降水量的异常敏感区域为粤西北区、粤西南区和粤东北区。三个区域近几年夏半年降水量均表现为减少趋势,其中粤东北区降水量减少幅度较大。

Analysis of Sensitive Area for summer half year precipitation in Guangdong province

Based on the summer half year precipitation data at 25 observational stations from 1980 to2012 in Guangdong province, the periodic oscillation and spatial anomaly features and time evolution rule were analyzed by wavelet analysis, EOF（Empirical Orthogonal Function） and REOF（Rotated Empirical Orthogonal Function） methods. The results indicate that the periodic oscillation of summer half year precipitation in Guangdong province presented as 4a、 7a and 13 a and the first principal period is 4a with most strong oscillation signal, the second and third principal period respectively for 7a and 13 a. The main anomaly structures present less or more in all the areas, and spatial changes are opposite pattern from the coast to inland. The anomaly sensitive areas are northwest area, southwest area and the northeast of coast. The trend of summer half year precipitation appears decreasing tendency in recent years and the northeast area reduces remarkably.