When flow velocity decreases below the corresponding incipient motion condition, no sediment movement occurs. 当水流速度小于相应的起始运动时，将无泥沙运动。
The physical pattern of sediment exchange and bed coarsening simulation was put forward, and long-term data on hydraulic-dynamics and sediment motions were modeled. 提出了泥沙交换和河床粗化计算模拟的物理图案，对长系列水动力和泥沙运动进行了模化处理。
