Numerical study on effects of building groups on dam-break flow in urban areas

In this study, the effects of flood waves on urban areas due to a dam failure are numerically investigated based on two physical experiments and a field study case. The numerical model is a two-dimensional unstructured finite volume model based on the shallow-water equations and well-balanced HLLC scheme. The predicted water depths are consistent with available laboratory measurements. In laboratory experiments, a relatively high water depth and the delay effects of flow at the front of urban areas are observed. The urban areas may become a large obstacle to the propagation of the flood wave. In the case study of the Tous Dam failure in Spain, the calculated water depths agree very well with those from existing numerical model, but some discrepancies still exist. Considering the uncertainty of field survey data, the water depths obtained from this study are quite reasonable.