斗门“龙舟水”时空特征及与天文潮的相关分析

Spatiotemporal Characteristics of“Dragon⁃Boat Racing Rains”in Doumen and Analysis of the Correlation with Astronomical Tides

利用斗门区1967—2022年“龙舟水”降水资料,通过M-K检验、Morlet小波分析、克里格网格化等统计方法分析“龙舟水”的时空分布特征,并对其与天文潮的相关性进行了讨论,结果表明:(1)近56年斗门区“龙舟水”的变化趋势不明显,呈轻微减少的态势;但出现异常偏多年份的概率相对偏高,占比达16.1%。(2)近56年斗门区“龙舟水”的时间变化具有显著的年际和年代际变化特征,并具有1~5年的变化周期。(3)M-K检验和滑动t检验表明斗门“龙舟水”降水量在1967—2022年间并未发生突变。(4)在空间分布上,受山脉地形影响,雨量大值区主要集中在斗门区的西部至南部及东北部地区,呈西南-东北走向,与境内山脉地形走向基本一致。(5)“龙舟水”峰值年的出现时间与天文潮朔、望日时间高度重叠,其中望日对“龙舟水”降水的影响更大,相关系数达66.7%。

Using the precipitation data for the so⁃called“Dragon⁃boat Racing Rain”(hereafter abbrevi⁃ated as“DBR rain”hereafter)from 1967 to 2022 in the district of Doumen,Zhuhai and with the statistical methods of Mann⁃Kendall abruptness test,Morlet wavelet analysis and Kriging,this paper analyzed the spa⁃tiotemporal distribution characteristics of the DBR rain.The result is shown as follows.(1)For the 56 years studied,the DBR rain varied insignificantly with slightly decreasing trends,though the probability for the years with abnormally more such rainfall to appear was relatively high(16.1%).(2)During the years of interest,the district’s DBR rain varied significantly on the interannual and interdecadal scales with oscilla⁃ting periods at one to five years.(3)As shown in the Mann⁃Kendall test and moving t⁃test,no abrupt chan⁃ges took place in the rainfall of the district’s DBR rain from 1967 to 2022.(4)On the spatial distribution,maximum rainfall zones mainly occurred in the west,south and northeast of the district,distributing in the SW to NE direction and showing a generally consistent orientation with the local mountainous terrain.(5)The peaks of the DBR rain were much superimposed with the time of astronomical tides associated with either the first or the last day of a lunar month(respectively for the cresent moon and the full moon).Particularly,the full⁃moon day had a greater impact on the DBR rain with a correlation coefficient of 66.7%.