Classification and Analysis of River Processes

Aerial photographs and brief field visits are frequently the only data sources for the preliminary design of river engineering works in romote or undeveloped areas. Even if short-term field data are available, they may be misleading because of the nonuniform rates at which river processes take place. The major active processes are, however, reflected in the river morphology so that correct classification and interpretation of channel, flood-plain, and terrace features on maps and photographs can, to some degree, overcome a lack of long-term data. Rivers present a wide spectrum of intermediate forms between the familiar classic braided and meandering types. This reflects a similarly wide spectrum of flow distribution, bed material size, sediment transport, and channel stability. Existing river classification schemes are reviewed and a modified system is proposed to take account of the gradual transition between classical types.