SELF-AFFINITY IN BRAIDED RIVERS

Three braided rivers of different scales and different hydrologic/geom orphologic characteristics (the Aichilik and Hulahula in Alaska and th e Brahmaputra in Bangladesh) are analyzed for spatial scaling using a logarithmic correlation integral method developed earlier by the autho rs. It is shown that the rivers exhibit anisotropic scaling (self-affi nity) with fractal exponents nu(x) = 0.72-0.74 and nu(y) = 0.51-0.52, the x axis being oriented along the river and the y axis in the perpen dicular direction. The fact that despite large differences in scales ( 0.5-15 km in braid plain width), slopes (7 x 10(-3) to 8 x 10(-5)), an d types of bed material (gravel to sand), the analyzed braided rivers show similar spatial scaling deserves special attention. It might indi cate the presence of universal features in the underlying mechanisms r esponsible for the formation of the spatial structure of braided river s. Also, comparison of fractal characteristics of braided rivers with those of single-channel rivers and river networks suggests that braide d rivers form a class of fractal objects lying between the classes of single-channel rivers and river networks.