粤港澳大湾区1961—2014年降水时空演变特征分析

Analysis on spatiotemporal evolution characteristics of precipitation in Guangdong-Hong Kong-Macao Greater Bay Area from 1961 to 2014

利用粤港澳大湾区31个气象站点1961—2014年逐日降水资料,采用Mann-Kendall非参数检验法、Hurst指数、小波分析法、经验正交函数(EOF)分解法等方法,分析区域年、季节降水时空演变规律。结果表明:1961—2014粤港澳大湾区降水波动较大,时空分布不均,年、冬季、春季降水量呈不显著上升趋势,秋季呈不显著下降趋势;春夏两季降水分别在1964—1965年和1965—1966年发生突变;降水变化的整体方向将继承过去的趋势,系统的平均循环长度分别为4 a、6 a、8 a、10 a和11 a;年降水量变化以28 a为主周期,以18 a、13 a和6 a为次周期;年降水量总体上从东南至西北呈现递减趋势;大湾区降水主要是全区一致的变化,其次为东部沿海地区及西北部封开、怀集地区与内陆地区反位向分布。

Based on daily precipitation data of 31 meteorological stations in the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)from 1961 to 2014,the Mann-Kendall nonparametric test method,Hurst exponent,wavelet analysis method,empirical orthogonal function(EOF)decomposition method and other methods were adopted to analyze the spatiotemporal evolution of annual and seasonal precipitation in the area.The results showed that the precipitation in the GBA fluctuated greatly from 1961 to 2014,and the spatiotemporal distribution was uneven.Annual,winter and spring precipitation showed insignificant upward trend,while autumn seasonal precipitation showed insignificant downward trend.Abrupt changes of spring and summer precipitation occurred during 1964-1965 and 1965-1966.The overall trend of precipitation will keep the same as the past.The average period length of the system is 4 a,6 a,8 a,10 a,and 11 a.The annual precipitation change has a main period of 28 a and secondary periods of 18 a,13 a and 6 a.In general,the annual precipitation showed a decreasing trend from southeast to northwest.The evolution of precipitation in the GBA is basically consistent across the whole region.Secondly,precipitation in the eastern coastal area(including the northwestern Fengkai and Huaiji)and the inland area are inversely distributed.