Field measurements of settling velocities of fine sediments in Three Gorges Reservoir using ADV  

作　　者：Wenjie Li Shengfa Yang Jiang Hu Xuhui Fu Peng Zhang 

机构地区：[1]National Inland Waterway Regulation Engineering Research Center,Chongqing Jiaotong University,66 Xuefu Road,Nan'an District,Chongqing 400074,China [2]Key Laboratory of Ministry of Education for Hydraulic and Water Transport Engineering,Chongqing fiaotong University,66 Xuefu Road,Nan'an District,Chongqing 400074,China

出　　处：《International Journal of Sediment Research》2016年第3期237-243,共7页国际泥沙研究（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(51209241);the Basic Research Project of China Ministry of Transport(2014329814310);the Social Livelihood Science And Technology Project of Chongqing(cstc2015shmszx30024)

摘　　要：The Three Gorges Reservoir （TGR） is suffering from unexpected fine sediment deposition, to better understand the fine sediment transport processes, field measurements were conducted at the Zhongxian and Fengjie reaches. A method based on the sediment diffusion equation was proposed to measure the settling velocities using the Acoustic Doppler Velocimeter （ADV）. The backscatter acoustic intensities （BSI） received from the ADV were calibrated against the sediment concentrations measured via water sampling, suggesting a linear relationship in double logarithmic coordinate system. The instantaneous sediment concentration was calculated using the derived relationship, and then the settling velocity was obtained through the proposed procedure. The settling velocities of the fine particles in the TGR were found to vary with the water depth. Most of the effective settling velocities were within the range of 0.1 - 10 mm/s, which were larger than those of the primary particles, indicating that the flocculation was likely to occur in the TGR. Additionally, it is suggested that the turbulent motion played an important role in the flocculation in the TGR.The Three Gorges Reservoir （TGR） is suffering from unexpected fine sediment deposition, to better understand the fine sediment transport processes, field measurements were conducted at the Zhongxian and Fengjie reaches. A method based on the sediment diffusion equation was proposed to measure the settling velocities using the Acoustic Doppler Velocimeter （ADV）. The backscatter acoustic intensities （BSI） received from the ADV were calibrated against the sediment concentrations measured via water sampling, suggesting a linear relationship in double logarithmic coordinate system. The instantaneous sediment concentration was calculated using the derived relationship, and then the settling velocity was obtained through the proposed procedure. The settling velocities of the fine particles in the TGR were found to vary with the water depth. Most of the effective settling velocities were within the range of 0.1 - 10 mm/s, which were larger than those of the primary particles, indicating that the flocculation was likely to occur in the TGR. Additionally, it is suggested that the turbulent motion played an important role in the flocculation in the TGR.

关 键 词：Settling velocity Fine sediments Acoustic Doppler Velocimeter Field measurement Three Gorges Reservoir 

分 类 号：TV145[水利工程—水力学及河流动力学]