Fractal Tree Analysis of Drainage Patterns

摘要

This paper presents an analysis of geometric properties for drainage structures to find out the valid range in which scale invariance of the channel network remains the same. To this end, a review of network patterns of bifurcation process is undertaken through fractal geometry, Strahler's stream ordering scheme and Horton's law. The complete drainage network is constructed by identifying all possible flow paths on DEM, which is fulfilling the drainage area through the connection of the channel network to hillslope path. The topology of resulting drainage network is assigned by Strahler's stream ordering scheme. There is a specific range where fractal properties of channel network are valid in a natural basin, which is related to divergent and convergent topography of a basin geomorphology. The general fractal dimension of the channel network for the basin of interest is approximately 1.68 to 1.8 showing a significant degree of space filling. The fractal property of drainage network would be valid within the extent of valley network including the whole channel network connected with transition portions on hillslope.