Abstract
The flood flows and river-bed variation of the Chikuma river with vegetation zone on major bed were analyzed. In this study, flood flows were assumed to be two-dimensional in horizontal direction, and the Galerkin finite element method was applied to the basic equations for spatial directions and the two-step Lax-Wendoroff method was employed for time direction. The hydrauric resistances of plants on major bed were idealized to dispersive resistance on river bed in one case or were culculated according to the water depths and the plant shapes in the other case. The analytical zone was from confluence of the Sai and Chikuma river to Tategahana, 13.5km length, about 1.0km width. The flood water levels measured ('83.9) and these numerical results showed good agreement.
