ON LANDSCAPE SELF-ORGANIZATION

A new quantitative characterization of landscape-forming processes in the general framework of self-organized criticality and of fractal ana lyses is proposed. The coupled processes considered are threshold-inde pendent hillslope evolutions and threshold-dependent fluvial transport phenomena. From a body of experimental and theoretical evidence we ar gue that geomorphological thresholds, principles of minimum energy exp enditure and concepts of self-organized criticality are of crucial imp ortance for the understanding of the basic general mechanisms which go vern landscape evolution. This paper considerably extends both the the oretical framework and the empirical evidence for a recently developed theory which incorporates the above general principles. The modeling of landscape evolution by principles of self-organization is accomplis hed through the introduction of diffusion processes operating mainly o n the hillslopes and the coupling of these processes with the fluvial evolution of the network previously studied through principles of self -organized criticality. The effects of spatial variability of surface erodibility are investigated under the general framework of random spa ce functions with a correlation structure. Finally, a fractal analysis of the characteristics of the resulting landscape is performed and co mpared with recent results from real landforms to suggest the relation ship of landscape fractal dimensions with the underlying landscape-for ming processes.