Sand-bed instability due to bed load motion.

Abstract

The lag of sediment transport for bed form plays an important role in sand bed instability. Instability analysis is compared with the theory of bed load transport. The lag distance of bed load transport rate for bed shear stress is clarified. The flow model based on the potential flow theory is improved by introducing the effect of flow acceleration or deceleration which can be expressed by local variation of flow depth and the phase lag between bed shear stress and bed form is estimated. After clarification of these lags, an instability analysis is conducted and the possibility of instability of bed surface is investigated against hydraulic conditions. -from ASCE Publications Abstracts