A-Gis Based Approach of an Evacuation Model for Tsunami Risk Reduction

Abstract

In a tsunami mitigation plan, evacuation plays a crucial measure for saving human lives, especially for communities who are living in low-lying coastal areas. In some locations, higher grounds may not exist or local tsunami make it not possible for community to evacuate to a distant location due to the short warning time. Thus, a possible solution is vertical evacuation into the upper level of buildings or structures designed to resist the effects of the tsunami. This research developed a method to choose the most effective evacuation routes using Geographic Information System (GIS) tools in a tsunami-prone area, the case of the Cilacap coastal area. Network analysis and various GIS techniques were used to determine the location and capacity of potential suitable evacuation shelter buildings (ESBs) and the most effective evacuation route for tsunami. The evacuation process used simulates that the residents of the inundation area will be encouraged to walk to safe areas in a certain amount of time. Results of the modeling include the proposed location of additional ESBs, the capacity and service area of each building, and the evacuation route for each center of population to reach the escape buildings. The number of additional shelters was different for the different-time scenario since daytime and nighttime scenarios will give a different distribution and different number of shelters needed. In addition, the effective evacuation routes were developed for each service area. In this case, travel time was an essential factor since it would limit the movement of evacuees in the evacuation process.