Geographia Polonica Vol. 82 No. 1 (2009)

24 cm

When estimating the reach of the flood zones, a mathematical model that describes the flood wave propagation, as well as the digital elevation models can be used. In this study, a two step approach has been applied. In the first step, in order to find the most relevant flooding areas, a one dimensional hydraulic model HEC-RAS has been used, which assumes steady state flow conditions and a discharge of Qp 1% = 7210 m3/s and Q p 0.1%= 9960 m3/s. The segment of the Vistula Valley analysed is 47.05 km long. In the second step, a smaller area has been analysed using the 2D hydraulic model of shallow water flow which is based on the Roe scheme of finite volume method.