The southern coastal area of Java Island is one of the nine seismic gaps that prone to tsunamis. The entire coastline in one of the regencies, Gunungkidul, is exposed to the subduction zone in the Indian Ocean. Also, the growing tourism industries in the regency increase its vulnerability, which places most of its areas at high risk of tsunamis. This conditions are expected to increase the tsunami risk and loss potential alongside the coastal area. This research aims to model tsunami inundation and estimate the loss that caused by tsunami. Detailed DEM generated from UAV photogrammetry. Based on the model, several inundation scenario. Based on the model, the 4-m inundation did not affect a wide area. The modelling proves that the extent of tsunami-inundated areas is directly proportional to the wave height of tsunamis. The inundated area extend as the inundation scenario increase. Hilly karst topography prevent the water to inundate wider areas. The loss calculation shows that the material loss at the trading centre was relatively much higher than the other land uses because its included not only the value of the building but also the commodities and the strategic importance of their market.

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Tsunami evacuation is a short process that must be carried out in minutes. Determining the evacuation routes and safe areas is equally important in tsunami evacuation planning. It can be established from least cost distance (LCD) anisotropic model. We use the coastal of Drini, Gunungkidul, Java, Indonesia, as the study area, which is located in a tropical coastal karst region, with a typical karst cone formation. The topographic condition of the karst cone could be an ideal location for tsunami vertical evacuation (TVE). High-resolution orthomosaic images and digital elevation model (DEM) generated from the structure from motion (SfM) process were used as the main data. The tsunami inundation model was calculated based on neighboring operations using raster calculator from the elevation value in the DEM. Land cover identification from high-scale orthomosaic images showed the variation in speed conservation values (SCVs). The slope value was also used as a surface cost that will affect the travel time to the TVE shelters. The results of the model show that TVE is the main alternative in tsunami evacuation planning beside horizontal evacuation. They provide an evaluation of the location of the assembly points and evacuation routes provided by the government, which have been considered ineffective because of the inappropriate model. The results of the study provide an overview of determining the evacuation routes and shelters. Optimum locations can minimize travel time, provide adequate capacity, and be safe from inundation.

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