Abstract
Gravel bed rivers transporting suspended sediment often have banks composed of fine sand (what we call “gravel bed sand bank morphology”). A theoretical model of the formation of “gravel bed sand bank morphology” is presented in this paper. The theory of equilibrium cross-section of sand-silt rivers is extended to include the case of gravel bed partially covered with fine sand. The theory shows that the location of sand deposition depends on the center depth, bed slope, sand size and sand supply. It is found that the bank regions tend to be filled with fine sand if center depth and bed slope are sufficiently large, and sand size is sufficiently small, and that the central bed region is covered with fine sand otherwise.
