Study on the starting principles of sediment by water force in Taihu lake

The starting principles of sediment in Taihu lake are simulated in an annular tank,the different stages of sediment movement are analyzed,and the changes of total phosphorus (TP) concentration in upper water with velocity are studied in this paper.The experimental results show that the incipient velocities of sediment in Taihu lake at three different incipient standards (individual movement,ounce movement,universal movement) gained from the lab experiments are 35,45 and 60cm/s respectively,and the observed TP concentration in the upper water varies significantly at the three starting velocities.In this paper,the theoretical sediment starting model is also used to calculate the incipient velocity and the incipient shear stress of Taihu lake at three different starting standards.The calculated values are 37.9,46.7,59.8 cm/s and 0.428,0.636 and 1.042 N/m²,respectively.It can be concluded that the starting velocities gained from the lab experiments and the model simulation are fairly applicable,which can basically reflect the actual starting state of sediment in Taihu lake.