鄱阳湖五河入湖水沙通量特征及驱动因素研究OA

[Objective]This study aims to reveal the long-term variation patterns,abrupt change characteristics,and driving factors of water and sediment fluxes of the five rivers into Poyang Lake,thereby providing scientific support for basin water re-sources management and water-sediment regulation strategies.[Methods]Based on runoff,sediment load,precipitation,and temperature data of the five rivers from 1960 to 2018,cumulative anomaly analysis,Mann-Kendall trend tests,Morlet wavelet analysis,and double mass curve methods were employed to systematically analyze the trends,abrupt change years,periodic features,and the contributions of climate change and human activities to water and sediment flux variations.[Results](1)The runoff from the five rivers into Poyang Lake remained generally stable throughout the study period,show-ing no significant long-term trend,whereas the sediment load declined markedly,with 1995 identified as the year of abrupt change and a reduction rate of 64.26%.(2)Runoff was dominated by short-term cycles of less than 10 years,associated with the regional monsoon climate,while sediment load showed long-term cycles exceeding 10 years,reflecting combined driving factors of climate change and human activities.(3)During the baseline period(1960-1995),the precipitation-sediment relationship remained stable.However,in the change period(1995-2018),the actual sediment load was much lower than the theoretical value,indicating that human activities significantly reduced sediment load per unit of precipitation.(4)Double mass curve analysis showed a stable precipitation-runoff relationship,whereas the slope of the precipitation-sediment relation-ship decreased significantly after 1995,indicating that sediment retention by reservoirs,soil and water conservation measures,and sand mining management were the dominant factors driving the sediment decline.[Conclusion]The sediment load processes of the five rivers into Poyang Lake have undergone significant changes after 1995,with human activities exerting a stronger regulatory effect than the direct impacts of climate change.Future basin management should integrate reservoir opera-tion optimization,soil and water conservation projects,and sand mining control policies to enhance long-term sediment man-agement and support ecological security in the Poyang Lake Basin.