Clear-water scour around a bridge abutment in the floodplain of a comp
ound channel was investigated. Experiments were conducted in a flume w
ith a fixed-bed main channel and a movable-bed floodplain in which the
abutment terminated. Flow depth, discharge, compound-channel geometry
, and abutment length were varied, and measurements of approach veloci
ty distribution and scour depth were obtained. A preliminary relations
hip for the dimensionless scour depth is suggested to illustrate the c
ompound-channel effects on scour. The proposed relationship is limited
to the range of values covered by the variables in this study.