Linking of 2D and Pipe hydraulic models at fine spatial scales

Linking of two-dimensional overland flow hydraulic models with one-dimensional storm water pipe models at very fine resolution is becoming a standard approach for urban flood investigations. This paper describes the application of such an approach to a variety of small, complex urbanised catchments in Australia and New Zealand. A benefit of this approach is that previously hidden information in terms of secondary flow paths and cross-flows become apparent, an outcome that is not possible with traditional 1D modelling tools. Generation of flood risk mapping is much simpler through the use of direct GIS interfaces to the model result files, making the modelling and presentation process much more transparent. The paper will describe the application of the models, the calibration approach and some specialised modelling techniques when working at such fine spatial resolution in urban environments.