A numerical model including river flood routing and surface inundation for river basin has been developed in this thesis. In the model the hydraulic interaction between the water stage in river and the outflow of subcatchment is taken into consideration. The model combines one- dimensional unsteady flood routing model in river system and two- dimensional overland inundation model in watershed. In the river system model, based on a one-dimensional dynamical wave and kinematic wave theory, the water stage and discharge in river system are solved by using the four-point implicit finite-difference scheme. In the watershed two- dimensional overland flow inundation model, based on the zero-inertial wave theory, is employed by the alternating direction explicit scheme. By using the two models, the inundation area, water
depth, and the outflow discharge of the effluent in the river basin are computed.
