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 events with deterministic transport processes, The numerical procedure calculates the runoff water discharge as a function of the return period of elementary 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 transport processes can be directly simulated in a intuitive way, relating the water flux and the local slope to the sediment transport activity. The present version of the code encompasses the main characteristics of erosion-sedimentation processes, from the simple hillslope diffusive law to the more complex nonlinear fluvial transport. To illustrate the versatility of the model to reproduce complex natural dynamics, we calculate several geomorphological instabilities which are crucial in relief dynamics. (C) 2001 Elsevier Science Ltd. All rights reserved.