Urban flood modeling using 1D-2D coupled Hydraulic Models

The development of a coupled one-dimensional/two-dimensional hydrodynamic model of Jinan city is presented in this study. Correct simulation and prediction of flood extents in urban areas has become a challenging issue. Numerical modeling of urban flood events often requires a simultaneous description of the flow through relatively narrow channel networks and across extended urban plains. One-dimensional models can describe flows in channels efficiently while two-dimensional models can make good results for overflow. The integration of a two-dimensional model with a one-dimensional model can give a full play to their own characteristics and advantages and resolve the problem in spatial resolution and calculation accuracy, frequently encountered while two models were used separately. The dynamic hydraulic model Mike Flood is used to model flood events of Jinan city. The model is constructed using topographic data for the study area and calibrated to surveyed flood levels for the July 2007 rainfall event. The results show that the model can effectively simulate the complex process of inundation in urban area, provide higher reliability of potential urban flood risk assessment and give a practical guidance on the regional water conservancy facilities and water resources management.