Author(s): Andrea Rinaldo; Ignacio Rodrigueziturbe

Linked Author(s): Andrea Rinaldo

Keywords: No Keywords

Abstract: Self-organized criticality (SOC) refers to the tendency of large dissipative systems with many degrees of freedom to build up a state poised at criticality that is characterized by a wide range of length and time scales. SOC is now a common name for a general theory of the dynamics of fractal growth, whose main features are recalled in this lecture, especially with reference to applications within the context of earth sciences. In this lecture we suggest that principles of critical self-organization are at work in the development of the fluvial landscape. We also show that optimal channel networks are spatial models of self-organized criticality. This reinforces earlier suggestions [Rodriguez-Iturbe et al, 1992; Rodriguez-Iturbe and Rinaldo, 1997] that natural fractal structures like river networks may indeed arise as a joint consequence of optimality and randomness. Specifically, we suggest that natural fractal structures in the fluvial landscape are dynamically accessible optimal states, corresponding to locally optimal niches of a complex fitness landscape where evolution can settle in a stable manner. Such relative stability is achieved with respect to perturbations and is nonetheless reminiscent if the dynamic history, including an imprinting of its initial conditions and long-lived signatures of boundary conditions, here surrogating geologic constraints.

DOI:

Year: 1997