A PHYSICAL STATISTICAL APPROACH TO EROSION

Erosion is a complex process consisting of many components such as sur face runoff, impact of raindrops, wind forces, soil and rock mechanics , etc. Trying to integrate all these processes into a physical model s eems to be hopeless. In order to understand the variety of natural sha pes and patterns produced by erosion we present an integrated statisti cal approach. Our model is based on simple physical constraints for th e separation of amalgamated particles (abrasion) and for the movement of loose particles (denudation) and on the laws of statistics. After s ome simplifications, we obtain a nonlinear system of partial different ial equations which is solved using finite volume techniques. The mode l is suitable for the formation of different types of rill systems and the episodic behaviour of erosion processes, a kind of self-organized criticality. Besides effects of inhomogeneities, e.g. the formation o f terraces can be investigated.