黄河下游水沙变化多时间尺度集对分析

Multiple time-scale set pair analysis on relationship between runoff and sediment in the Lower Yellow River

为认识黄河下游水沙变化在不同时间尺度下的关系结构及整体变化趋势,在采用经验模态分解方法对黄河下游4个水文站1960-2016年的径流量和输沙量时序进行多时间尺度分解的基础上,对各站年径流量和年输沙量不同时间尺度分解序列的丰枯相关性进行集对分析。结果表明:黄河下游各站年径流量和年输沙量的变化呈减少趋势,且均存在3个不同的波动周期。在短波动周期内,年径流量与年输沙量变化具有丰枯同步特性。随着波动周期增加,年径流量与年输沙量出现丰枯不同步的可能性逐渐增大,且越靠近下游,出现丰枯不同步的可能性越小,在长波动周期上,年径流量与年输沙量会出现丰枯相反的状态。

A multiple time-scale decomposition of annual runoffs and suspended sediment loads from 1960 to 2016 were conducted at four hydrological stations,and a rich-poor correlation relationship between decomposed-serials of annual runoff and suspended sediment load on different time scales were analyzed by set pair analysis. Results show that three fluctuation periods for annual runoff and sediment series in the Lower Yellow River were existed,and their residual functions are reduced significantly. The annual runoff synchronized with sediment load in short fluctuation period. The probability of rich-poor asynchronism of annual runoffs with sediment loads increased gradually in longer fluctuation period. The lower the reach location,the smaller the asynchronism probability is. In the long fluctuation period,the annual runoff and annual sediment transport will be in the different state.