The problem was to define quantitatively and qualitatively, for alluvial channels, selected aspects of form and fluvial processes which contribute to the development of fluvial systems. A five-stage model is proposed to explain the development of alluvial channels. The model is based upon channel morphology, channel morphometry, and qualitative conclusion based on numerous field observations. A generic classification is suggested, which permits hierarchical ranking of common bed forms in straight, sinuous, and meandering alluvial channels. Two major subdivisions: channel-forming and channel-altering bed forms are proposed.