Tsunami inundation and vulnerability analysis on the Makran coast, Pakistan

Abstract

The coastal cities of Gwadar and Pasni, situated along the Arabian Sea in the northwestern region of the Indian Ocean, are subjected to thorough investigation for inundation and vulnerability analysis. The estimation of maximum tsunami wave potential in the Arabian Sea involves evaluating paleomorphodynamic records of tsunamites found along its coastlines, with a focus on the most severe case for modeling to determine the maximum wave potential. Subsequently, based on this assessment, three distinct wave scenarios (7, 10, and 15 m) are projected onto Pasni and Gwadar and their surrounding coastal areas. The results reveal the high vulnerability of both cities to wave heights ≥7 m and wavelengths ≥15 km, with the 15 m scenario posing a near-complete disaster for both cities and adjoining towns. Furthermore, simulation results demonstrate that the coastal orientation and morphology contribute to the devastating impact of reflection, integration, and amplification phenomena in the region, with their intensity escalating with larger approaching waveforms. The reflection-amplification phenomenon notably and variably impacts inundation extents and depths. The installed tsunami early warning system's effectiveness is also evaluated based on the modeling and simulated results and the recent practices of early warning alerts issued.