抄録
Numerical simulations for flood flows and bed variation in a symmetrical river confluence were performed using a quasi-three dimensional numerical model. The vertically averaged and moment equations was used as governing equations to allow for the incorporation of pre-assumed linear distribution of horizontal velocity distributions. The model is based on finite volume method using HLL(Harten, Lax and van Leer(1983)) and HLLC(Harten, Lax and van Leer and Contact(2004)) numerical flux, which is one of a Riemann solver. The model is verified against two experimental data of flows and bed variation in symmetrical river confluence. It shows that the model can reproduce the complex behavior of the flows and bed variation with reasonable accuracy.