抄録
In order to enable accurate predictions of the bedform change in rivers, the accurate estimation of the sediment transport rate is important. In this study, we propose a bedload formula taking into account the effect of the pressure gradient in flow caused by the formation of dunes on the basis of Kovacs & Parker's formula including the effect of the local bed inclination. We performed a nonlinear stability analysis by the use of the sediment transport formula derived in this study. It is found that the transition between dune-covered and flat bed transition is charactrized by subcritical bifurcation even if the effect of the local bed inclination is large.
