1980－2018年山西省太行山南麓暴雨时空变化特征

基于1980-2018年山西省太行山南麓晋城市5个站点的降水资料,利用小波分析和Mann-Kendall方法,研究了太行山南麓暴雨时空变化特征。结果表明:39年平均年暴雨日数有0.9个,年际变化幅度较小。暴雨量与暴雨日数的空间分布并不一致,1980、1981、1982、1995和1996年暴雨日数较多。分析50-59、60-69、70-79、80-89、90-99、100以上6个暴雨量区间空间分布发现,暴雨的空间分布在不同区间并没有明显的趋同性。年暴雨降水量有不同程度的增加趋势,晋城市下辖5站暴雨量趋势均存在突变,突变时间存在差异,暴雨量在19811983年和19921995年为两个峰值时段,之后有所缓和。39年暴雨时间序列的小波波谱显示,太行山南麓暴雨呈现0~3 a、3~7 a、8~24 a等3类周期准振荡变化规律,各波动周期稳定性和显著性不同。3~7 a出现5个多少准周期振荡,该周期表现较为显著,8~24 a出现2个准振荡周期,且这两个周期非常稳定,具有全域性的特征。晋城市3~7 a的暴雨振荡周期和8~24 a特大暴雨振荡周期与现实非常吻合。

Spatiotemporal Variation Characteristics of Rainstorm in the South Foot of Taihang Mountains in Shanxi Province from 1980 to 2018

Based on the precipitation data of five stations in Jincheng City at the south foot of Taihang Mountains in Shanxi Province from 1980 to 2018,the temporal and spatial variation characteristics of rainstorm at the south foot of Taihang Mountains are studied by using wavelet analysis and Mann Kendall method.The results show that the average annual rainstorm days in 39 years are 0.9,having a smaller interannual variation range.The spatial distributions of rainstorm volume and rainstorm days are not consistent.Many rainstorm days appeared in 1980,1981,1982,1995 and 1996.The rainstorm volume interval space is divided into six sections 50—59,60—69,70—79,80—89,90—99 and more than 100 for analysis.It is found that the spatial distribution of rainstorm in different sections has no obvious convergence.The annual amount of torrential rains has an increasing trend in varying degrees.There is a sudden change in the rainstorm trend at the five stations of Jincheng City at different times.The rainstorm volume had two peaks in 1981—1983 and 1992—1995,and then eased.The wavelet spectrum of the 39-year rainstorm time series shows that the rainstorm at the south foot of Taihang Mountains presents three types of periodic quasi oscillation variation laws,such as 0—3 years,3—7 years and 8—24 years.The stability and significance of each fluctuation cycle are different.There are five more to less quasi periodic oscillations in 3—7 years,which are more significant.There are two quasi oscillation cycles in 8—24 years,which are very stable with regional characteristics.The rainstorm oscillation periods of every 3—7 years and the severe rainstorm oscillation period of 8—24 years in Jincheng City are largely consistent with the observed facts.