关键词: 悬浮物浓度, 湍流动能, 底泥起悬, 表层沉积物, 水-土界面, DBS浓度仪, 太湖,

Abstract: Taihu Lake is a typically large shallow lake with eutrophication.Sediment suspension due to hydrodynamic disturbance at sediment-water interfaces has a close relationship with cyanobacteria bloom.In this study,we collected synchronous data including weather,hydrodynamics,water quality by Acoustic Doppler Velocimeter,Optical Backscatter Sensor,PH-II Handheld weather stations in Taihu Lake.Then,we analyzed the relationship between suspended matter concentration and wind speed,shear stress and turbulence characteristics.The results showed that the shear stress caused by wave played a leading role in the process of sediment resuspension in the central Taihu Lake.Besides,thresholds of wave shear stress and wind speed were 0.08 N/m2 and 4 m/s respectively.Also,sediment resuspension was mainly caused by intermittent bursting of turbulence in coherent structures.The large amplitude disturbance in a short time played a key role in sediment vertically diffusion.This study could provide references for endogenous release mechanism related to turbulence in Taihu Lake.

Key words: suspended matter concentration, turbulence kinetic energy, shear stress, surface sediment, sediment-water interfaces, Optical Backscatter Sensor, Taihu Lake