| We measured the cross-sectional flow velocities in the tree zone of the Otofuke River during a flood[*]caused by Typhoon Etau in August 2003 and tried to clarify the flow conditions at that time. It was[*]confirmed that the obtained flow pattern of cross sectional distribution sufficiently reproduced behavior[*]of the flow velocity in the tree zone.[*]The calculated average flow velocity in the tree zone was about 0.12 - 0.27 m/s、 which was 1/15th that of[*]the main stream、 whose average velocity was 3 m/s without trees. Discharge from the vegetated section[*]accounted for about 6% of total section. And it has become necessary to examine the existing methods of[*]measuring tree density . |
