Physical Environment and Human Context at Merapi Volcano: A Complex Balance Between Accessing Livelihoods and Coping with Volcanic Hazards

Merapi is a two-sided, paradoxical volcano: on the one hand 1.8 million people live on its flanks. It is one of the most densely populated volcanoes on Earth, with population densities averaging 764 inhabitants per square kilometre within a 10 km radius from the summit. The main reasons for the high densities are land resources and associated livelihoods from agriculture, livestock, sand mining, and tourism. On the other hand, Merapi is also one of the world’s most active volcanoes. Dome-collapse pyroclastic density currents (PDCs) occur every few years (e.g. 1994, 2002, 2006), and more violent explosive episodes are generated with an average recurrence interval of several decades (e.g. 1872, 1930, 2010). Risk management at Merapi is based on volcanic hazard zonation (called KRB I, II, and III, from the less exposed to the most exposed), derived from its eruptive history. Since its first publication by the Volcanological Survey of Indonesia in 1978, the danger map has been updated twice, in 2002 and after the deadly eruption of Merapi in 2010. Most of the information is provided by scientists during the ‘raising awareness program’ phase and achieved in the framework of a Community-Based Disaster Risk Management (CBDRM), which empowers communities with self-developed ways of coping with crises due to natural hazards. In periods of emergency, the Center for Volcanology and Geological Hazard Mitigation provides four warning levels of volcanic activity. In 2010, Merapi produced its largest eruption since 1872, damaging around 12,000 buildings, claiming 367 lives, including 200 directly by PDCs, and triggering massive evacuations of up to 400,000 people, as counted in the evacuation camps.