More than 1300 people living on the slopes of Indonesia’s Mount Merapi were killed when it erupted in 1930. As one of Indonesia’s youngest and most active volcanoes, the aptly named ‘Mountain of Fire’ keeps nearby villagers on tenderhooks. But today, volcanologists can predict Mount Merapi’s activity and plan responses.
In 2006, when Mount Merapi began to rumble, pouring out lava and spewing hot volcanic ash and smoke, authorities ordered mass evacuation. They established an escape route and set up shelters away from predicted lava flow and noxious gases. Although the eventual 2006 eruption was considered mild - the 2.5-mile cloud of hot ash and gas never reached populated areas - volcanologists warned the volcano could collapse at any time.
With this in mind, researchers at the Centre of Volcanology and Geological Hazard Mitigation have been working to curtail the death and destruction that follows an eruption. 'Our priority is to save lives,' said Dali Ahmad, a volcanologist at the centre. 'Knowing the location of shelters beforehand helps us prepare support for the evacuation process. We can improve roads and buildings and establish support facilities such as health clinics. We can also calculate the shortest evacuation routes.'
With 129 active volcanoes in Indonesia, disaster planning is a hefty task. It is made simpler with the use of mapping and database technology. In preparation for an eruption, scientists use GIS to determine areas that will be clear of lava and mud flow to establish evacuation shelters in safe locations. They also use satellite images and continuous monitoring to detect changes in volcanic activity.
The centre runs a GIS based on ESRI's ArcGIS technology. The system generates 3D views of the activity under the volcano. Population centres or critical infrastructure can be layered in the GIS relative to the position of volcanoes to plan evacuations. Hazard zones can be modelled based on topographic data. It can also be used to predict areas of potential inundation by a lahar (a muddy landslide of volcanic debris and water).
In many eruptions, lahars are the main cause of death. The lahars from the Nevado del Ruiz eruption in Colombia in 1985 caused the Armero tragedy, which killed an estimated 23,000 when the city of Armero was buried under 5 metres of mud and debris.
Source: www.asmmag.com
