Abstract: In this article, a mathematical model of flood routing is established by finite volume method based on two-dimensional unsteady flow equations. An improved water balance model is applied to the flood routing calculation to solve the problem of false flow in the unit of mountainous area. According to the boundary condition deter-mined by the flood process of Taolinkou reservoir, the submerged area, submerged depth and flow fields in the downstream mountainous area are calculated in consideration of the influence of mountainous terrain on flood routing. Furthermore, the values of flood marks on the riverbank were adopted for model validation, and the simulation results are overall consistent with historical observed data. On the basis of flood routing simulation, the economic and life losses caused by flood disaster are estimated. The research result provides necessary ideas and methods for impact assessment of regional flood control.

Key words: finite volume method, flood routing, water balance, Taolinkou reservoir, flood loss assessment