抄録
There are two theories about the origin of river meanders: one is based on the bed-instability theory and another one is on the bend-instability theory. According to the bed-instability theory, the meanders will be developed due to alternate bars on the bed. Although this theory was occasionally denied in the bend-instability theory because of reasons that typical wave number of developed alternate bars falls in the stable range of bend instability and so on, meanders induced by alternate bars are often seen in natural rivers in Japan. The theoretical verification of this kind of meander generation is required. In this study, the linear stability analysis is applied to the straight channel with erodible banks in order to obtain the characteristics of the meanders. The results indicate that meanders induced by alternate bars will exist and they have longer wavelength than that from previous bar-theory. And, it was found that Froude number is the one of the parameter that affects the wavelength of these meander types.
