Reza Barati - Ph.D. candidate - Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran.
Seyed Ali Akbar Salehi Neyshabouri - Prof. - Water Engineering Research Center, Department of civil Engineering, Tarbiat Modares University
Goodarz Ahmadi - Prof. - Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York

Particle movement will take place when the instantaneous fluid force on a sediment grain isjust larger than the instantaneous resisting force [1]. In order to consider differenthydrodynamic forces which exert on the grain, Newton’s second law can beutilized in aLagrangian perspective

Incipient, Threshold, Motion, Sediment, Discrete Element Method