GIS in disaster management: a case study of tsunami risk mapping in Bali, Indonesia

Tsunami events in many regions of the world show that this hazard is highly significant and has had a considerable impact at the local level, bringing death or injury to human beings and damage to the environment. The tsunami risk cannot be eliminated, but it can be effectively analyzed and possibly reduced by using the proper tools and models to produce reliable and meaningful estimates of the tsunami risk facing the coastal communities. A method for assessing the tsunami risk is by modeling using Geographic Information System (GIS) technology since the tsunami risk is spatially variable and GIS can help to understand such variability once the data base have been constructed.\ud \ud The overall aim of this thesis is to create a model of tsunami risk assessment that can be applied and used anywhere in coastal Indonesia by using Geographic Information System (GIS) technology. The research outcome will give information to local people that live in tsunami–prone areas, and local governments to aid them in the development of tsunami mitigation planning that includes city development planning, land use zoning and regulation, economic improvement activities, education and awareness campaigns, and evacuation planning. A quantitative and qualitative approach is used to achieve the following objectives: (i) develop a generic model of tsunami risk assessment that incorporates physical, social, economic and city infrastructure factors that can be adapted for other coastal locations and jurisdictions, (ii) develop a spatial methodology to integrate multiple factors and measure the hazard, vulnerability and risk of tsunami hazard, and (iii) apply the tsunami risk assessment framework in Kuta and Sanur Regions as a case study.\ud \ud Kuta and Sanur Regions that are located in Bali are vulnerable to the tsunami hazard because Bali is located on the boundary of the Eurasian and Indo–Australian Plates, which move occasionally. This movement can generate submarine earthquakes which are one of the factors that can generate a tsunami. Despite the fact that Kuta and Sanur Regions are at risk from tsunami impact, there is no information about the distribution of vulnerability in these regions and their risk of tsunami hazard.\ud \ud The model presents hazard, total vulnerability and risk maps. The hazard map is based on the inundation zones. The total vulnerability map is based on the combination of physical, social and economic factors. The risk map is based on the combination of hazard and total vulnerability scores. The results show that Kuta, Legian and Sanur Villages in Kuta and Sanur Regions may possibly be at risk from future tsunamis. Therefore, local governments should focus on these villages. In this thesis, the author also included the research frameworks for each assessment that can be applied in other parts of coastal Indonesia and used by local government staff who have GIS knowledge to create maps based on the available resources in their areas.\ud \ud The outcome of this thesis will be useful for local government to create regulations that relate to the construction of new buildings in the coastal area, for disaster planners and emergency managers to create tsunami mitigation in the future, and for coastal communities in the study area to be aware, prepare, know and learn the early signs of tsunamis in the future