Effect of Merapi Disaster Evacuation on Road Network Performance in Yogyakarta Special Region

The eruption of Mount Merapi, located  in Sleman Regency, Yogyakarta Special Region, in the past inflicted heavy casualties. Evacuation of refugees to safe places was a must in order to minimize casualties. In order to identify the extent of changes in road network performance due to disaster evacuation, evacuation modeling is required to optimize the handling in the future. This study was conducted with the help of SATURN version 11.3.12W. This model also involved 140 centroid, 449 buffer node, and 589 segments. The rise and pull as travel inputs included daily OD matrix and simulation of refugees covering 50%, 60%, 70%, 80%, 90% and 100% of the total directly affected population in ring 1. The results of the study showed that there was an increase in the flow and travel times of road network existing in Sleman Regency, either ring 2, ring 3 or the road network outside the rings. There was a decrease in performance in ring 1 because all road networks were only used by refugees in one direction from home to ring 2 in order to keep away from the disaster source. The coverage of  evacuation movement did not affect the movement existing in the areas of Yogyakarta City, Bantul Regency, Kulon Progo Regency and Gunung Kidul Regency. Furthermore, it was necessary to carry out an evacuation simulation  in ring 2 and ring 3 in order to expand the coverage of the affected area and the extent of the effect of performance changes in the existing road networks.