ANISOTROPIC SCALING IN BRAIDED RIVERS - AN INTEGRATED THEORETICAL FRAMEWORK AND RESULTS FROM APPLICATION TO AN EXPERIMENTAL RIVER

Dynamic scaling in braided rivers is reexamined under an extended theo retical framework, developed herein, which explicitly incorporates the self-affinity (scaling anisotropy) in the spatial structure of braide d rivers. It is shown that in structures exhibiting anisotropic spatia l scaling, dynamic scaling (if present) is necessarily anisotropic. Th rough analysis of the behavior of an experimental braided river, the p resence of anisotropic dynamic scaling in braided rivers was revealed. This implies that there exists a pair of dynamic exponents z(x) and z (y) enabling one to rescale space (differently in the direction X of t he slope and in the perpendicular direction Y) and time, such that the evolution of a smaller part of a braided river looks statistically id entical to that of a larger one. The presence of such a space-time sca le invariance provides an integrated framework for describing simultan eously the spatial and temporal structure of braided rivers and may be explored toward statistical prediction of large and rare changes from the statistics of smaller and frequent ones.