赣江流域降水时空分布特征

Temporal and spatial distribution characteristics of precipitation in Ganjiang river basin

基于赣江流域内44个站点的59年(1960~2018年)的逐月降水量资料,采用累积距平、滑动t检验、小波分析、EOF分解等方法,分析了赣江流域降水的时空分布、趋势、突变和周期特征.研究表明:赣江流域降水量年内分配不均,1~6月逐渐增多,6月以后急剧减少,降水量以18.8mm/10年的速率增多,降水量空间呈现‘中间少四周多’的分布;1991年降水出现了由少到多的突变,2002年为由多到少的突变,降水主周期为35年,并伴有6年、12年、18年的次周期;降水的前3个模态累积贡献率达82.9%,3种模态表征的降水分布主要为空间一致型、南北相反型、中部与南北相反型.

Aiming to prove the temporal and spatial variation of precipitation in Ganjiang river basin.Based on the monthly precipitation from 44 national meteorological stations in the basin for 59 years(1960~2018),the cumulative anomaly method,sliding t test,wavelet analysis,EOF decomposition and other methods were used to analyze the temporal and spatial distribution,trend,abrupt change and periodic characteristics of precipitation in the Ganjiang river basin.The research shows that:The distribution of precipitation in the Ganjiang river basin is uneven during several years,gradually increasing from 1 to 6 and decreasing sharply after June;precipitation increased at a rate of 18.8mm/10 years.The precipitation space shows a distribution of‘less in the middle and more in the surroundings’;the precipitation in 1991 showed abrupt changes from low to high,and in 2002,there was a sudden reduced change in precipitation.The main cycle of precipitation is 35 years,with sub-cycles of 6,12,and 18 years;the EOF analysis results of precipitation show that the cumulative contribution rate of the first three modes is 82.9%.The precipitation distribution types characterized by the three modes are mainly spatially consistent,north-south reverse,middle and north-south reverse.