Experimental study of bed surface fractional characteristics and bed form resistance in meandering channels

The riverbed morphology is quantitatively evaluated using the generalized data from flume experiments to calculate the fractal dimension of riverbed surface(hereinafter referred to as the BSD).Discussions are given on the method of BSD calculations,on the fractional characteristics in meandering channels,as well as on the relationship between the BSD and the bed form resistance.The result shows that the BSD value is able to represent the longitudinal change in talweg,transverse geometric changer in foreshores and deep channels.The scouring and silting extent or bending river bed surface,exhibits clear fractal characteristics.BSD can be used as a measure of the bed surface roughness height.The relationship between the BSD and the bed form resistance is thus established.The bed form resistance is proportional to BSD.There are two distingue regions in the different relationship between the BSD and the bed form resistance,and can be identified by flow rates.