1. Mapping Dangerous Zone of Galunggung Volcanic Mountain Using ArcGIS

2. Introduction Location 7°15′0″S 108°3′0″E Brief Information/history Mount Galunggung, is an active stratovolcano in West Java, Indonesia, part of the Sunda Arc Extending through Sumatra, Java, and Bali, which has resulted from the subduction of the Indian oceanic plate and the Australian plate beneath the Eurasian Plate.

3. The last major eruption on Galunggung was in 1982, which had a Volcanic Explosivity Index of 4 and killed 68 peoples. This eruption also brought the dangers of volcanic ash to aviation worldwide attention. It was reported, some airplanes were affected by the volcanic ash and cause the emergency landings.

4. Eruption photo of Galunggung in 1982

5. Mapping Dangerous Zone of Galunggung Mountain Ideas Recent eruption happened on Merapi Volcano Mountain has impacted to other volcano mountains. It was reported, the volcanic activities around several mountains were increased soon after the Merapi’s erruption happened. Galunggung Mountain was noted to have increasing volcanic activities related with Merapi’s erruption. Eventhough government already anticipate the recent situation, apparently they don’t provided with any adequate data such as “Dangerous zoning” map of Mount Galunggung. It is important to note, in the volcanic disaster management, the adequate data is one requirement to make right decision. To help “decision maker” doing their job, we create the dangerous zoning map of Galunggung Mountain.

6. Data and Tools Requirements 1. Geographical Map of Galunggung 2. GIS Software (I use ArcMap and ArcCatalog version 9) 3. Computer. Concepts 1. Mapping dangerous zone is based on lava movement 2. Lava is considered as the liquid phase like the water that flow through the earth surface (hill, and valey) and then gather at the catchment area. 3. Thus, we made the map based on the slope of the mountain, run-off, catchment area, the distance from the main crater

7. Procedure of Works Load the contour map

8. Create TIN layer

9. From TIN we create the Slope Map

10. Create Catchment Map using ArcHydro tools

11. Created Weighted Flow Accumulation by using ArcHydro tools

12. Reclassify the Slope layer

13. Reclassify the elevation layer

14. Convert Raster to Features, Slope

15. Convert Elevation layer to feature

16. Convert catchment into feature

17. Convert weighted flow accumulation to feature

18. Add the zoning layer

19. Using Union tools to combine all the feature layers

20. Using dissolve tools, we get result of zoning map based on value that existed on every area