The Impacts Analysis of Pre And Post Merapi Mount Eruption on Residential Areas Using Sentinel 1, ALOS Palsar and Landsat Satellite Images Combination in 2009-2015

Abstract

Indonesia is a country located in the presence of three large tectonic plates like the Indo-Australian, Eurasian and Pacific plates. The path of plate movement approaching or steering away each other leads to high volcanic and earthquakes activity. As a proof of the active path of this plate movement can be seen from the series of active volcanoes lies from the island of Sumatra, Java, Nusa Tenggara into Papua. The impact of active volcano activity will be felt in the densely populated area where the island of Java became one of the islands with the largest residential area in Indonesia. This impact needs to be anticipated with an integrated high-tech technology and volcanic disaster mitigation system. One of the most active volcanoes in the island of Java is Merapi mount which is experienced the last major eruption peak on October 26th, 2010. This volcanic eruption is effusive eruption type where magmatic gas pressure in the crater is not too strong and magma eruption is just flowing out past the slopes of the Merapi mount area. However, magmatic gas pressure and magma volume still result in deformation changes that have a direct impact on residential areas throughout the Merapi mount area. Therefore, this research performs deformation calculation using DInSAR (Differential Interferometry Synthetic Aperture Radar) method on Sentinel 1 SAR and ALOS PALSAR 1 satellite images between 2005-2015 acquisition year. Then the deformation patterns obtained from the DInSAR method will be spatially correlated with residential areas throughout the Merapi mount area. Residential areas were obtained through supervised classification process from Landsat 5 and 8-satellite imagery in the 2005-2015 acquisition year. The reason of observation year selection is based on pre and post eruption concept to get pattern of Merapi’s mountain body change through deformation analysis. The result of the combination of deformation pattern and residential area changes was further analysed to obtain spatial correlation. The value of this spatial correlation will be an indicator of how’s far the deformation changes due to volcanic activity will have an effect on the residential areas in the Merapi mount area. The output of this research is a map of Merapi mount deformation (due to volcanic activity) impacts on the residential area. The results are expected to contribute to the volcanic disaster mitigation system and the development of residential area plans in Merapi mount area.