Geospatial Information Analysis Based on Numerical Modelling of Tsunami Inundation in Coastal Area of Temon District, Kulon Progo Regency

Abstract

Abstract The southern coastal area of Java Island is a subduction area confluence of the Eurasian Plate and the Indo-Australian Plate. The southern area of Temon District, Kulon Progo Regency includes the Central Java-East Java megathrust area. Megathrust Central Java-East Java has a maximum earthquake potential of 8.9 Mw which has the potential to cause a tsunami disaster. The built-up land area in Temon District has a potential threat from the danger of tsunami inundation. The purpose of this study is to (1) analyze the danger of tsunami inundation in Temon District and (2) determine the area of built-up land affected by tsunami inundation. The method used in this study is descriptive quantitative-qualitative. TUNAMI-N3 was used in numerical modelling to determine tsunami inundation hazards and Google Earth Engine was used in analyze built-up land in Temon District. The results of tsunami inundation hazard treatment and built-up land areas were analyze using ArcGIS 10.8 to determine built-up land affected by the potential tsunami inundation hazard. The results showed that the tsunami generated from the earthquake scenario with a magnitude of Mw 8.9 had a maximum height of 19.86 meters with an average travel time of 33 minutes to reach the coastal area of Temon District. Temon District affected by tsunami inundation hazard has a tsunami area of 2.47 km2 with details of a low tsunami danger level of 0.67 km2, medium tsunami danger of 0.95 km2 and high tsunami danger of 0.85 km2. The maximum height of the tsunami inundation bath is 6.54 meters. Temon District has a built-up land area of 14.308 km2. Built-up land affected by tsunami inundation is 0.55 km2 with details of 0.14 km2 at low danger of tsunami inundation, 0.20 km2 at medium danger of tsunami inundation and 0.21 km2 at high tsunami inundation hazard.