The 24th IAHR-APD Congress (24th IAHR-APD Congress)

524 / 2024-06-29 20:00:55

Changes of Water and Sediment Characteristics in the Middle Reaches of the Yangtze River in Recent 40 Years

runoff, sediment, Changes in water and sediment, wavelet analysis

Subtheme 7: Sediment Regulation and Management > Topic 4: Sediments and Environment

Based on the hydrological data of Yichang station and Hankou station in the middle reaches of Yangtze River from 1970 to 2013. Based on the Mann-Kendall trend test and continuous wavelet analysis, the seasonal variation of water and sediment characteristics and the trend of water and sediment change were analyzed. The results show that the time series of water and sediment in Yichang station and Hankou station have multi-level time-scale structure. In the 23-32 years, 10-19 years, 2-10 years time scale, the same site of the runoff and sediment transport cycle is basically the same. But the runoff of different sites and the change period of sediment transport are not correspondingly corresponding to the corresponding time scale. Yichang station and Hankou annual runoff in 40 years although there are fluctuations, but the amplitude is not obvious. The MK test values of Yichang station and Hankou station were -5.59 and -6.83 respectively, and the annual sediment transport capacity at both sites showed a steep trend. The main reason is due to the Three Gorges Project water storage and sediment interception.