Pakistan suffered from a devastating flood disaster in 2010. This study investigated the potential of utilizing a rainfall-runoff-inundation (RRI) model for providing useful information for effective emergency response. The model was applied to the entire Indus River Basin (modeled area: 929,723 km2 with 60 sec. (about 1.7 km) grid-cells, and its performance was evaluated based on the simulation results of river discharge and flood inundation. More specifically, a large-scale flood extending about 100 km apart from the main Indus River was focused for testing the model performance. Furthermore, by comparing different modelling settings including one- and two-dimensional kinematic and diffusive wave approximations and different treatments of embankment, the study discussed a suitable model structure to achieve the above objective with limited information. As a result, two-dimensional diffusive wave rainfall-runoff-inundation simulation without explicit considerations of embankment turned out to be the best combination for large-scale flood simulation for the case of the 2010 Pakistan flood.
