An integrated tsunami inundation and risk analysis at the Makran Coast, Pakistan

Abstract. The coastal cities and areas of Gwadar and Pasni in Pakistan, being highly vulnerable to tsunamis, are investigated for inundation and risk analysis. For modelling, both dynamic and static approaches are used for better understanding and for their comparative analysis. The tsunami wave potential in the Arabian Sea is estimated by compiling and assessing the palaeo-morphodynamics of tsunamite record discovered so far along its coastlines. The dynamic model is calibrated and validated with the inundation limits of the 1945 tsunami in the Pasni area. Further, for risk estimation, three different wave scenarios (7 m, 10 m, and 15 m) are projected on Pasni and Gwadar. Results show that both cities are highly vulnerable to wave heights ≥7 m and wave lengths ≥ 15 km. The 15 m scenario would be almost a complete disaster for both cities and adjoining towns. Results of simulation and comparative analysis also show that due to coastal orientation and morphology, the reflection, integration, and amplification phenomena have a devastating effect on the region, and their intensity increases with the increasing size of the approaching waveform. It variably but significantly affects the inundation extents and depths. At the end, based on the simulated results, the utility of the installed early warning system is assessed.