The main contents and conclusions are as follows : 1 . the dynamic pressure on the original riverbed and the scour hole are measured . the results show that the characteristics of dynamic pressure in the scour hole are the same as that on the original riverbed 表明在基岩冲刷过程中以及冲坑稳定后，射流冲击区的脉动压强与冲坑形成前一样，都是以低频大振幅为主，说明在冲刷坑形成后，射流冲击区水流与无冲坑时一样，都是大尺度涡不断破碎和小尺度涡不断生成的过程。
