Critical condition between scour and siltation in the Yellow river

The characteristics of scour and siltation in the middle and lower Yellow River channels is reviewed in this paper.The relation of discharge and sediment concentration under critical conditions between scouring and siltation was derived and compared with the field data of the Yellow River and its tributaries.It is shown that the Yellow River scours when river flow is relatively clear and silt up when the flow is relatively muddy,the critical values between relatively clear and relatively muddy can be calculated.