複断面蛇行河道の平面形状特性と蛇行度, 相対水深を用いた洪水流の領域区分

抄録

According to previous studies of compound meandering channel flow based on laboratory and natural streams data, two different flow characteristics have been identified; simple meandering channel flow and compound meandering channel flow. The existence of both characteristics depends on sinuosity, depth ratio and other parameters. These results become important information to design river structures and for river improvement. However, quantitative evaluations of the effect of plan shape, cross-sectional shape and hydraulic condition on the flow characteristics have not been investigated well. In this paper, we conducted experiments with small sinuosity channel (s=1.028) to study the effect of sinuosity and main channel width and relative depth. Thereafter, we compared our laboratory results with field data from 10 Japanese compound meandering rivers so that the effect of plan shape was analyzed. Finally, it showed that classification of the different flow characteristics of compound meandering channels were based on the representative parameters sinuosity, depth ratio, location of maximum velocity filament and maximum scouring depth at meander apex section.