Spatial model of vulnerability to tsunami in Buleleng Sub-district

Abstract

Buleleng Sub district is the activity center in Buleleng Regency. It is adjacent to the Bali Sea in the northern part, which is crossed by the Flores back arc thrust fault. Considering the fact that the fault activities in Flores had caused an earthquake and tsunami in 1992 in Flores which killing up to 2100 people and in 1976 in Buleleng Regency, hence a spatial modelling for tsunami vulnerability in Buleleng Sub district was developed. The aim of this study was to analyze the tsunami elevation model, and to analyze the integration of tsunami-exposed areas with the distribution of populations and buildings in Buleleng Sub district. The methods used for making a spatial modelling for tsunami vulnerability in Buleleng Sub district were quantitative analysis and spatial analysis. Analytical Hierarchy Process (AHP) used to determine the value, weight, and score. Built land variables distinguished the residential buildings, and trade and service areas. Distribution variables used an estimation of per 10 hectares in the grid. Based on the results, there are three wave height scenarios to identify how big the tsunami exposure area is in Buleleng Sub district. The scenario of 6-meters shows the number of victims will reach up to 2,493 people and around 482 buildings will affect. While, the 9-meters scenario estimates that there will be 147,276 victims and 8,052 buildings will affect. The last scenario is the 20-meters that estimates around 161,199 people and 18,293 buildings will affect.