Tsunami hazard mapping and loss estimation using geographic information system in Drini Beach, Gunungkidul Coastal Area, Yogyakarta, Indonesia

¹ Department of Environmental Geography, Faculty of Geography, Universitas Gadjah Mada, Indonesia  
² Department of Geographic Information Science, Faculty of Geography, Universitas Gadjah Mada, Indonesia  
³ Master Program in Planning and Management of Coastal Area and Watershed, Universitas Gadjah Mada, Indonesia  
⁴ CV. Mitra Geotama Mapping Consultant, Yogyakarta, Indonesia

^* Corresponding author: arismarfai@ugm.ac.id

Abstract

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.