2001 Volume 45 Pages 481-486
Aerial photographs of 1998 flood flow in the Tone River were analyzed by cross-correlation method to obtain velocity vectors over the flow surface. Characteristic features of flow downstream of bridge piers were examined by using the data. It was pointed out the discharge measurement by float estimates larger discharge than real one.
Features of velocity distribution and of the cross section profile of river bed were examined to get the guide-line on choosing the appropriate cross-section for discharge measurement.