Numerical modeling of Tsunamis and Tsunami vulnerability analysis of temon coastal region in Yogyakarta, Indonesia

Tsunamis are deadly natural disasters in coastal areas and with rapid developments taking place in these regions, the tsunami vulnerability index is projected to increase. Tsunamis can be simulated as long waves and modeled using the Shallow Water Equations (SWE). This study simulates the run-up and inundation of tsunamis generated by earthquakes at the southern subduction zone for the coast in Temon, a district in Kulon Progo, Yogyakarta, Indonesia. The purpose of this study is to assess the coastal vulnerability to tsunamis and to map the inundated areas. For this reason, we used an approach that implemented hydrodynamic simulations into numerical models from accurate bathymetry and topographic data. Digital Terrain Model (DTM) derived from Small-Format Aerial Topography and the National Bathymetry Data (BATNAS) were used to model the potential of tsunami propagation from the earthquake source. We defined vulnerability to tsunami as a function of population, roads, and infrastructure and analyzed it based on the maximum reach of inundation from the coastline in GIS software. Tsunami hazard is a combination of tsunami inundation area and maximum flow depth. Tentative vulnerability data, as identified using GIS software, was supported by data acquired during field survey and population data estimates. Our results were vulnerability maps showing that in daytime scenario, tsunamis affected more than 40,000 people. © 2020, World Research Association. All rights reserved.