SELF-ORGANIZATION AND LANDSCAPE EVOLUTION

Self-organization is common in earth surface systems, and related prin ciples have been proposed as general principles applicable to geomorph ic systems. Non-self-organizing behaviour is also observed in geomorph ic systems, however. If a reasonable box-and-arrow diagram and associa ted qualitative interaction matrix can be devised for a geomorphic sys tem, one can determine whether or not (or under what conditions) the s ystem is self-organizing, Both self-organizing (at-a-station hydraulic geometry) and non-self-organizing (soil landscape evolution) geomorph ic systems are illustrated. The development of topographic relief demo nstrates the principle that landscape evolution may be characterized b y both modes at different times or under different circumstances. Incr easing relief, involving a mean divergence of elevations, may be self- organizing. Topographic development by decreasing relief, where elevat ions generally converge, is always non-self-organizing Self-organizati on in geomorphology may be similar to steady-state equilibrium, in tha t its explanatory value lies not in general applicability, but in dist inguishing between fundamentally different modes of landscape developm ent.