Validation of the physical modelling approach for braided rivers

G. Rosatti

in WATER RESOURCES RESEARCH, v. 38, n. 38.12 (2002), p. 31-1-31-8



Laboratory channels are often used to study the complexity of braiding mechanisms

for the advantages with respect to field studies. Nevertheless, the extensive use of
experimental data raises the question of how representative laboratory braided channels
are as compared to real braided rivers. This study verifies to what extent laboratory
braided patterns reproduce the main features of braided rivers. Experimental data display
isotropic and anisotropic scaling of braided patterns, state-space plot of total widths,
anisotropic scaling of islands, and statistical distribution of island areas that are similar to
those observed in real rivers. Moreover, the data reveals scaling in the perimeter-area
relation. These results support both the reliability of experimental braided channels as
physical models of braided rivers and also the possibility of investigating some aspects of
braiding in the laboratory that are difficult to address in the field. The lack of preferential
scales in island characteristics suggests that other phenomena must play a key role in
generating island shapes besides classical sediment transport-based mechanisms which
tend to select well-defined length scales.


download PDF