Abstract
In natural rivers, it is commonly seen that gravel beds are delineated by sandy banks. A theoretical model to explain the “gravel bed sand bank morphology” of straight rivers is presented in this study. The theory of stable cross-section of gravel rivers is combined with that of sand-silt rivers by introducing the concept of an available function (P) of fine sands on gravel beds. The theory predicts the location of sand deposit in the channel for given center depth, slope and center value of P (available function).
