The future tsunami risk potential as a consequence of building development in Pangandaran Region, West Java, Indonesia

This research is aimed to analyze the potential risk of tsunami in the Pangandaran region, consist of Pangandaran beach and Batuhiu beach area based on the increasing number of buildings over the last 10 years after the 2006 tsunami. This study used a descriptive comparative method, i.e. by comparing the number of buildings in 2017 with the number of buildings before the 2006 tsunami event. It was derived from high resolution images for the year 2006 and the aerial photographs from Unmanned Aerial Vehicle (UAV) for the year 2017. The exposed buildings are then superimposed with potential tsunami inundation zones based on the scenario of the 2006 tsunami to estimate the tsunami risk. The potential loss caused by the potential tsunami was calculated by considering the number of buildings loss potential. Many new buildings have been built from 2006 to 2017. In 2017, the number of buildings in Pangandaran beach becomes more crowded (1052 buildings) than in the 2006 post-tsunami event (921 buildings). Most of them are used for hotels and some small shops. In Batuhiu beach, the distribution pattern of the building is parallel to the coast, following the existing road network. Based on the September 2006 satellite imagery, the number of buildings remained there were 47 buildings. After recovery, the number of buildings becomes 261 or more than 5 times additional buildings. The total amount of loss due to the potential tsunami in Pangandaran and Batuhiu can reach exceed 200 billion IDR. Several action plans can be proposed, especially for evacuation infrastructure and capacity improvement for tourist and residents.