bed scour meaning in English

河床冲刷
河底冲刷

Observation and analysis of the river bed scour behind the third dam of gutianxi
古田溪三级大坝下游河床冲刷原型观测与分析
The mathematical model was applied to serve the engineering projects . the different water levels and flow discharges in nanjing river reach are calculated , bed scour and sedimentation in this engineering reach during one hydrologic year are verified . all results are in good agreement with field measurements
西气东输过江工程，采用该模型模拟南京西坝泗源沟河段不同流量水流运动，并计算一水文年过程该河段的河床冲淤变化，结果和实测资料也基本一致。