广东北江流域降水时空分布及其与Nio 3区SST相关性分析

Analysis of Correlation between the Spatio-Temporal Distribution of Precipitation in Beijiang River Basin and SST in Nio 3

论文选取广东省北江流域18站1965—2007年月降水数据,应用REOF方法将月降水量场划分为4个子区域,利用Mann-Kendall方法进行趋势检验,并采用滑动t检验方法进行变点分析,结果表明:流域东南部年降水量呈减少趋势,西北部呈增加趋势,年降水量增加变点出现在1992、1993年。选取REOF各分区最大特征向量载荷的站作为基准站,采用Morlet小波、交叉小波变换和小波相干分析其周期特征及其与Nio 3区SST相关关系,结果表明:4站月降水量周期变化均与Nio 3区SST相关显著;时滞相关分析表明,南雄、佛冈、连南三站月降水量变化与Nio 3区SST相关性在滞后3、4个月时最强,而三水站在同期相关性最强,这种差别可能与三水附近地区近几十年来受到的人类活动影响较强有关。

The paper analyzed the precipitation spatio-temporal distribution in Beijiang River Basin of Guangdong Province based on monthly and annual data of 18 stations from 1965 to 2007. The non-parametric method of Mann-Kendall is applied, and the result shows that precipitation of the whole basin has an insignificant upward trend from 1965 to 2007. The result of the moving t-test indicates that the increasing change points of precipitation appeared in 1992 and 1993. The basin was divided into four different subareas by REOF method. The paper selected subareas of characteristic vector of the largest load site as the benchmark station, and analyzed the cycle characteristics and the relationship between the precipitation and SST in Nino 3 by the continuous wavelet transform, cross wavelet and wavelet coherence techniques. The results show that monthly precipitation of four stations have significant correlation with SST in Nifio 3. The time-lag correlation analysis shows that there is the strongest correlation between monthly precipitation and SST in Nino 3 at later 3 and 4 months in Nanxiong, Fogang and Liannan stations, but Sanshui station at the same time. This difference may because that Sanshui area had the influence of human activity more intense than others.