A stochastic "precipiton" model for simulating erosion/sedimentation dynamics

We present a stochastic modelling of erosion-sedimentation processes. based on cellular automata, which mimics the natural variability of climatic eve nts with deterministic transport processes, The numerical procedure calcula tes the runoff water discharge as a function of the return period of elemen tary walking elements. This procedure generates water flux distributions at each point of the system, that depends on the local drainage area. and on the walker rainfall, and that are statistically analogous to natural river discharge distributions. It happens that a wide range of non-linear transpo rt processes can be directly simulated in a intuitive way, relating the wat er flux and the local slope to the sediment transport activity. The present version of the code encompasses the main characteristics of erosion-sedime ntation processes, from the simple hillslope diffusive law to the more comp lex nonlinear fluvial transport. To illustrate the versatility of the model to reproduce complex natural dynamics, we calculate several geomorphologic al instabilities which are crucial in relief dynamics. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.