A new quantitative characterization of landscape-forming processes in the general framework of self-organized criticality and of fractal analyses is proposed. The coupled processes considered are threshold-independent hillslope evolutions and threshold-dependent fluvial transport phenomena. From a body of experimental and theoretical evidence we argue that geomorphological thresholds, principles of minimum energy expenditure and concepts of self-organized criticality are of crucial importance for the understanding of the basic general mechanisms which govern landscape evolution. This paper considerably extends both the theoretical framework and the empirical evidence for a recently developed theory which incorporates the above general principles. -from Authors
