Research And Analysis Of River Network Structural Fractaility Based On DEM

Hydrology is one of the important aspects of geographical research, it mainly studies the existence of a variety of water, circulation and distribution.River is an important part of hydrology, domestic and foreign scholars for the study of river network structure mostly only stay on the surface geometry, without regard to the topological relationship between the river’s own mternalorganization.Many scholars show that the river network has self similarity and scale invariance in the whole, that is to say, the river has the characteristics of fractal geometry.River network fractal dimension between1.0 to 2.0, the value of geometric fractal dimension show that thedifferent development of river network.This paper usedArcgisanalysising and comparing the DEMs of 19 cities, in Sichuan province, computing terrain roughness and mean slope of these DEMs, found that terrain roughness and mean slope was positive correlation.Alsoextracted the cities’s river network and watershed based on the surface runoff flow model, programed based on Shreve stream to extract the largestsubwatershed of each cities. Simulatedriver network by dual graph with hierarchical structure, based on the dual graph, used the Maximum Excluded Mass Burning (MEMB)algorithm calculating the of river networks, the MEMB is a sophisticated algorithm of complexnetwork. Fittedbox size and corresponding box number with the linear fitting, found that the values of structural fractal dimension in studying areas river networkbetween3.1 to 4.41.The result verificated that as complex network,the river networks have the the characteristics of fractal geometry,also havestructural fractality.Combined with fractal geometry, found that structural fractal dimension is positively correlated withthe complexity of the terrain in same area.Meanwhile the fractal and self-similar property of river networkshelp maintain the unity of chaos and order in system, contrastwith human system can be found on the transformation of natural,relationship between human and landis always moving in the direction of symmetry. These conclusions are in favor of studyingimpact of human activities and natural environmental changes in hydrological cycle, have important significant in sustainable using of waterresources and understanding of nature and transforming the world.’...