PROBABILITIC HAZARD ASSESSMENT OF TEPHRA FALLOUT DEPOSIT OF SINABUNG VOLCANO USING TEPHRAPROB

• Main Author: ZAKI - NIM: 10213015, MUHAMMAD
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29373
• Institution: Institut Teknologi Bandung

<p align="justify">Indonesia is within the borders of two large plates, Euro-Asia and Indo-Australia, hence there are many active volcanoes. Two of the destructive materials during volcano eruption are lava and pyroclastic flow. The damage caused by tephra is not the most destructive, but the tephra disaster is a large-scale disaster, from a proximal location (several kilometers) to distal (hundreds of kilometers). Forecasts and mitigation in volcano disaster are usually done traditionally based on volcano monitoring and geological records. The geological record is very important in understanding the behavior and history of the volcano, but it is not yet sufficient to provide data on the variations of volcanic processes and the impact on the surrounding environment. Numerical modeling combined with probability analysis can be a complement to direct observation in understanding possible eruption scenarios to produce more accurate disaster forecasts. In this research, the probability model of tephra deposit from Mount Sinabung is modeled for the analysis of disaster. The TEPHRA2 model can provide a map of the distribution of tephra deposits using eruption data and atmospheric conditions, such as wind velocity and direction data, based on mass conservation equations influenced by advection and diffusion events. The modeling of tephra distribution using TEPHRA2 can be used to analyze the probability of disaster occurring in the eruption occurrence of a Volcano. The probability calculation system uses Tephraprob. Wind data used is data from National Oceanic and Atmospheric Administration (NOAA) and European Centre for Medium-Range Weather Forecasts (ECMWF). The eruption data is obtained from the Centre for Volcanology and Geological Hazard Mitigation (CVGHM) monitoring report from 2013 to 2017. Modeling on another mountain and deterministic modeling on Mount Sinabung is done to compare TEPHRA2 model results to field data. Then, probability of distribution of tephra deposit of Mount Sinabung is modeled with the wind data from 2010 to 2017. Probability of tephra mass accumulation, isomass map of tephra, and the hazard curve is obtained. The TEPHRA2 model is less suitable for use in deterministic modeling but provides the appropriate results in probabilistic modeling. The likelihood of the heaviest tephra deposit in the loading of 100 kg/m2 with damage to buildings in Bekerah Village. Other villages have a probability of damage to agricultural land, pollution of water sources, and disruption of electricity sources.<p align="justify">