基于小波变换的黄河宁夏段水沙变化趋势研究

Evolution Law of the Runoff and Sediment Discharge in Ningxia Reach of the Yellow River Based on Wavelet Transform

近年来黄河宁夏河段水沙特性及变化趋势受到大型水库运行调蓄影响,为探明其水沙演变规律,运用累积距平法及小波变换方法系统地分析了黄河下河沿水文站和石嘴山水文站连续63 a年径流量和年输沙量的演变规律。研究表明:宁夏河段年径流量存在6、9、13、28 a的变化主周期,水沙变化均有下降趋势。年径流量受龙羊峡水库运行影响,突变点出现在1968年和1986年,1986年的突变强于1968年的。宁夏河段年输沙量波动是祖厉河、清水河和红柳沟泥沙的汇入导致的。受刘家峡水库运行影响,年输沙量的突变点出现在1968年,在1968年以后年输沙量未出现明显突变。

In recent years,the characteristics of water and sediment in the Ningxia reach of the Yellow River have been affected by human activities and the operation and storage of large-scale reservoirs.In order to explore the water and sediment evolution laws,the cumulative anomaly method and wavelet transform method were used to analyze the water and sediment evolution laws of runoff and sediment transport for 63 years at the Yellow River Xiaheyan Hydrological Station and Shizuishan Hydrological Station.The research shows that the runoff of the Ningxia section has a main cycle of 6 a,9 a,13 a,and 28 a,water and sediment changes have a downward trend.The annual runoff is affected by the operation of Longyangxia Reservoir.The mutation points appeare in 1968 and 1986 and the mutation intensity in 1986 is greater than that in 1968.The reason for the fluctuation of sediment transport in the Ningxia reach is due to the influx of sediment from the Zuli River,Qingshui River and Hongliu Gulley.Affected by the operation of the Liujiaxia Reservoir,the sudden change in the annual sediment delivery occurs in 1968 and there is no obvious sudden change in the annual sediment delivery after 1968.