水库运行对径流—泥沙关系的影响分析

为研究水库运行对水沙关系的影响,以黄河上游龙羊峡水库为例,采用CEEMDAN方法对建库前后水沙序列进行多时间尺度分析,并与集对分析和信息熵理论相结合,分析水沙随机变化复杂性及水库运行对水沙关系的影响。结果表明,建库前水沙各序列具有较好的相关性,水库运行对多时间尺度下水沙关系影响显著;径流量、输沙量在短周期上以同一度和联系度为主,在长周期上以对立度为主,且水库运行后二者之间的同一度和联系度减小,差异度和对立度增大;水库运行后径流量与输沙量的熵值同步变化的关系被打破,二者之间熵值年际变化较稳定,说明水库运行改变了水沙同步变化的关系。

Influence Analysis of Reservoir Operation on Relationship between Runoff and Sediment Discharge

In order to study the influence of reservoir operation on the relationship between runoff and sediment discharge, the Longyangxia Reservoir was taken as an example. The multi-time scale analysis of runoff and sediment discharge sequence before and after the reservoir construction was carried out by using CEEMDAN method. Combined with set pair analysis and information entropy, the complexity of the random variation of runoff and sediment discharge and the impact of reservoir operation on the relationship between runoff and sediment discharge were analyzed. The results show that the sequence of runoff and sediment discharge before the reservoir construction has a good correlation, and the reservoir operation has a significant impact on the relationship between runoff and sediment discharge at multi-time scales. The runoff and sediment discharge are mainly based on identity and connection in a short period, and the contrary is dominant in the long period. After the reservoir operation, the identity and connection are reduced, and the discrepancy and contrary increase. The relationship between the entropy of the runoff and the sediment discharge is synchronously broken. The inter-annual variation of entropy between the two is relatively stable, which changes the relationship between runoff and sediment discharge.