Effect of Emergency Measures to Minimize Debris Flow Disaster after the Pyroclastic Material Deposition in Gendol River due to the 2010 Eruption of Mt. Merapi, Indonesia

Naryo Widodo, ST., MT, Suyanto, ST., M.Tech, Ir. Tri Bayu Adji, MA and Masaharu MIZOGUCHI

In 2010, the largest eruption in record occurred at Mt. Merapi in Indonesia. The largest pyroclastic flow which occurred on November 5, 2010 completely buried the valley of the middle reach of the Gendol River. Due to the river blockage, the risk of debris flow inundation in rainy season was increased. In order to guide debris flow to downstream, Mt. Merapi Lahar Control Office carried out emergency measures consisting mainly of temporary guide channel work of 23~30 m width and embankment work during the rainy season between 2010 and 2011. Although the inside of the pyroclastic flow deposit was high-temperature, the construction work had to be implemented using general heavy equipment. As a result, the construction work with excavation volume of 1.3 million m3 was achieved and effectively prevented the debris flow disaster. This paper describes the outline and effectiveness of the emergency measures so that it can be applied in other volcanoes in the future.

2018/1 243-248