近50 a腰古站流量变化特征分析

Analysis on the Characteristics of Flow Change at Yaogu Station in the Past 50 Years

为研究新兴江流域年平均流量的变化特征,以腰古站为对象,采用了Mann-Kendall检验法和Morlet小波分析法对腰古站年平均流量趋势变化及多时间尺度周期变化进行了分析。结果表明:近50 a新兴江流域年平均流量流量呈现下降趋势,下降趋势约为每10 a 2.4 m3/s,其中汛期以每10 a 3.4 m3/s减少,非汛期以每10 a 1.4 m3/s减少;年平均流量存在枯—丰循环交替的周期变化,具有5 a、13 a和22 a尺度周期,随着时间的推移,周期震荡强度先逐渐减弱后逐渐增强,且汛期平均流量周期变化规律与年平均流量较一致。预测2020—2025年前后流域年平均流量在5 a和13 a时间尺度上处于偏枯期;在22 a尺度上,流域年平均流量处于偏丰期。

In order to study the change characteristics of the annual average flow in the Xinxing River Basin,the Yaogu Station was taken as the object,and the Mann-Kendall test method and the Morlet wavelet analysis method were used to analyze the annual average flow trend and the multi-time-scale periodic change of the Yaogu Station.The results show that in the past 50 years,the annual average flow of the Xinxing River Basin has shown a downward trend,with a downward trend of about 2.4m3/s per ten years,of which 3.4m3/s per ten years in flood seasons,and 1.4m3/s per ten years in non-flood seasons.s decreases;the annual average flow has a cycle of dry-to-rich cycle alternately,with 5a,13a,and 22a scale cycles.As time goes by,the cyclical oscillation intensity first gradually weakens and then gradually increases,and the average flow cycle change during the flood season is the same as that of the year.It is predicted that around 2020-2025,the average annual flow of the basin will be in a relatively dry period on the 5a and 13a time scales,and on the 22a scale,the annual average flow of the basin will be in a relatively rich period.