Paper:

# Numerical Simulation of Mt. Merapi Pyroclastic Flow in 2010

## Makoto Shimomura^{*,†}, Raditya Putra^{**}, Niken Angga Rukmini^{**}, and Sulistiyani^{**}

^{*}Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University

1722-19 Sakurajima-Yokoyama, Kagoshima 891-1419, Japan

^{†}Corresponding author

^{**}BPPTKG, Center for Volcanology and Geological Hazard Mitigation, Geological Agency of Indonesia, Yogyakarta, Indonesia

A pyroclastic flow is one of the most dangerous hazardous phenomena. To escape a pyroclastic flow, the influenceable area must be evacuated before the flow occurs. Therefore, to predict the inundation area of a pyroclastic flow is important, and numerical simulation is a helpful tool in this prediction. This study simulated a pyroclastic flow by reproducing the pyroclastic flow of Mt. Merapi that occurred in 2010. However, necessary detailed information of the flow to conduct the simulation, such as total volume and the property of the pyroclastic flow material, flow rate, etc., were not available. Therefore, 20 simulations were conducted, varying the important conditions, such as the volume of pyroclastic material, inter-granular friction factor, and duration of the flow. The results showed that the volume of the pyroclastic material and inter-granular friction factor strongly control the flow characteristics. However, the friction factor does not result in a wide range of values; therefore, volume is the most influencing factor. The most suitable condition is a total volume of pyroclastic material of 30 × 10^{6} m^{3}, a 5 min duration of flow, and a 0.6 friction factor.

*J. Disaster Res.*, Vol.14, No.1, pp. 105-115, 2019.

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