2000 Volume 44 Pages 825-830
Damage caused to herbaceous vegetation on two gravel bars by the 1998 and 1999 floods in the Nagata Reach of the Tama River can be divided into four types according to their damage extent. In Type 1 (severest), vegetation including roots was totally washed away. In Type 2 (second severest), all stems were sharply cut off at their bases and washed away, but their roots remained. In Type 3 (third severest), longitudinal strips of vegetation washed away and buried were formed in a Type4 area. In Type 4 (mildest), vegetation uniformly fell down intact in the flow direction (partly buried). Significant correlation between destruction type and Shields number for surface gravel suggested that different gravel movement caused different destruction types. By estimating possible gravel actions on vegetation, destruction processes to the four types were identified.
