西江中游水沙序列的多时间尺度特征

小流域的水沙多时间尺度周期变化分析可为中长期水沙预测提供科学依据,为西江中游水沙序列的多尺度特征提供工程参考依据.选用红水河迁江站1957-2016年年径流和年输沙量数据资料,采用Mann-Kendall趋势检验、小波分析法和耦合关系模型,分析迁江站主要的水沙序列周期及其多时间尺度变化特征.结果表明:迁江站年水沙序列具...

Multi-time-scale Characteristics of Water-sediment Series in the Middle Reaches of the Xijiang River

An analysis of multi-time-scale periodic changes of water and sediment in small watersheds can provide a scientific basis for medium and long-term water and sediment prediction,and provide an engineering reference for the multi-scale characteristics of water and sediment sequence in the middle reaches of the Xijiang River.The annual runoff and annual sediment transport data of the Qianjiang Station of the Hongshui River from 1957 to 2016 is selected,and the Mann-Kendall trend test,wavelet analysis and coupling relationship model are used to analyze the main water-sediment series cycle and its multiple time at Qianjiang Station Scale change characteristics.The results show that the annual water-sediment sequence at Qianjiang Station has a downward trend,the multi-scale characteristics are basically the same and the main cycle exists.Human activities,climate fluctuations and water and soil conservation measures have a direct impact on the changes of the water-sediment sequence.The first major cycle of the runoff sequence is 25~30 a,the second major cycle is 13~24 a,and the third major cycle is 3~12 a;the first major cycle of the sediment transport sequence is 20~30 a,and the second major cycle is 9~20 a,The third main period is 3~9 a.On the time scales of 5,16 and 28 a.Due to the influence of the ecological environment and human activities,the water-sediment sequence has become more turbulent,and the final sediment transport sequence tends to be stable compared to the runoff sequence,and its change is also lagging behind the runoff sequence.In the coupling relationship,R2 of the runoff sequence is 0.43,and the sediment transport sequence is 0.71.The significance of the sediment transport sequence is higher than that of the runoff sequence;and human activities use science and technology to alleviate the contradictions of the original water and sediment system by affecting the sediment transport system.Even the solution makes the water-sediment system in the middle reaches of the Xijiang River enter the regeneration period.