Abstract

Volcanic ash represents a serious hazard to communities living in the vicinity of active volcanoes in developing countries such as Indonesia. Geoscience Australia (GA), the Australia–Indonesia Facility for Disaster Reduction (AIFDR) and Badan Geologi (Indonesia's Geological Agency) have adapted an existing open-source volcanic ash dispersion model for use in Indonesia. An application example is presented here for Gunung Ciremai in West Java, Indonesia. A stochastic set of eruption events was simulated using eruptive parameters within the acceptable range of possible future events for this volcano: granulometry and a meteorological dataset that represents the complete range of possible wind conditions expected during seasonal wind conditions for the region. Implications for nearby communities of dry v. rainy season conditions on volcanic ash hazard were investigated. Communities on the western side of Gunung Ciremai were highly susceptible to volcanic ash ground loading regardless of the season: communities on the eastern side, however, were more susceptible during the rainy season months. This is attributed to prevailing wind conditions during the rainy season that include a strong easterly component. Disaster risk reduction workers can use hazard maps like those produced here to inform decision-making, and to focus mitigation efforts on communities most at risk.