MIGRATION AND EXPANSION OF MEANDER LOOPS: A SIMULATION MODEL

摘要

This paper presents a model for simulation of the plan evolution of alluvial meandering streams, through downstream migration and lateral expansion. In agreement with conditions prevailing in natural streams, the flow is rough turbulent, the width-to-depth ratio is large and the Froude number is small. The flow rate is constant, the plan shape of the meandering stream is sine-generated. The channel displacement is accomplished through the action on the banks of the convective vertically-averaged meandering flow. The growth (expansion) of meander loops is attributed to the regime-trend. Preliminary results of application of the model show that the computed migration and expansion patterns are in good agreement with observations and measurements carried out in freely meandering streams.